ST75C540FP-A ,SUPER INTEGRATED DEVICESWITH DSP, AFE & MEMORIES FORTELEPHONY,MODEM, FAXOVERINTERNET& POTSLINESFUNCTIONAL DESCRIPTION. .... ... ... .... .. .. .. .... .. .. .. .... .. .. .. ... 13V.1 SYSTEM ARC ..
ST763 ,3.3V STEP DOWN CURRENT MODE PWM DC-DC CONVERTERSAbsolute Maximum Ratings are those values beyond which damage to the device may occur. Functional o ..
ST763A ,3.3V STEP DOWN CURRENT MODE PWM DC-DC CONVERTERSABSOLUTE MAXIMUM RATINGS Symbol Parameter² Value UnitV DC Input Voltage-0.3 to 12 VCCV Switch ..
ST763ACD ,3.3V STEP DOWN CURRENT MODE PWM DC-DC CONVERTERSAbsolute Maximum Ratings are those values beyond which damage to the device may occur. Functional o ..
ST763ACDTR ,3.3V STEP DOWN CURRENT MODE PWM DC-DC CONVERTERSABSOLUTE MAXIMUM RATINGS Symbol Parameter² Value UnitV DC Input Voltage-0.3 to 12 VCCV Switch ..
ST78C34CJ44 , GENERAL PURPOSE PARALLEL PRINTER PORT WITH 83 BYTE FIFO
STR-A6169 , Universal-Input/5 W Flyback Switching Regulator
STR-A6169 , Universal-Input/5 W Flyback Switching Regulator
STR-A6169 , Universal-Input/5 W Flyback Switching Regulator
STR-A6251 , Universal-Input/15 W 50 kHz Flyback Switching Regulators
STR-A6251 , Universal-Input/15 W 50 kHz Flyback Switching Regulators
STR-A6251M , Universal-Input/15 W 67 kHz Flyback Switching Regulator
ST75C540FP-A
SUPER INTEGRATED DEVICESWITH DSP, AFE & MEMORIES FORTELEPHONY,MODEM, FAXOVERINTERNET& POTSLINES
ST75C530
ST75C540SUPER INTEGRA TED DEVICES WITH DSP, AFE& MEMORIES
FOR TELEPHONY, MODEM, FAX OV ER INTERNET& POTS LINES
February 1999
TQFP80(14x14x 1.4mm)
(Full Thin PlasticQuadFlat Pack)
ORDER CODE: ST75C530FP-A
ST75C540FP-A
SUMMARIZED FEATURES(for detailed features,see page4). SINGLE CHIP FAXUpto 14.4Kbps(V.17). FULL DUPLEX DATA MODEM UP TO
14.4Kbps(V.32Bis). DIGITAL ANSWERING MACHINE: 4.8Kbps VOCODER VARIABLEPLAYBACKSPEED(+50%to -50%) ADPCM32,34, 16Kbps VOCODER. FULL-DUPLEX DIGITAL SPEAKERPHONE
WITH ECHO CANCELLATION. PROGRAMMABLE RING DETECTION.16 PROGRAMMABLE TONE DETECTORS
FOR CLID AND SCWID. DTMF DETECTION. VERSATILE HOST INTERFACES.16 GENERAL PURPOSEI/O PORTS.2 RELAY DRIVE OUTPUTS. SINGLE5V POWER SUPPLY. TYPICALACTIVEPOWER CONSUMPTION:
650mW (ST75C530), 750 mW (ST75C540). LOW POWER MODE< 30mW. 80-PIN TQFP PACKAGE (14mmx 14mm)
DESCRIPTIONST75C530 and ST75C540 are two super-inte-
grated devices including DSP, Modem and Audio
Analog Front Ends and memoriesfor Telephony,
Modem and FAX applications.
These devices canbe usedfor classical applica-
tions over POTS linesor over Internet.
The super integration technology allowsa signifi-
cant cost reductiononbillof materialsfor equip-
ment like High-End phones, INTERNET phones,
phone-Fax,INTERNET FAX,...
The devices are used witha host processor
througha Dual Port RAM allowingthe useof any
kindof microcontroller (RISC, CISC, General Pur-
pose 8-bitμC,...).
The embeddedsoftware includes: handsetwith listening group capability,full duplex handsfree, voicecoder/decoderat 4.8Kbpsfor staticanswer-
ing machine applications and ADPCM 16Kbps,
24Kbps and 32Kbpsfor high quality message
recording, Toneand DTMF generators, Toneand DTMF detectors, FAXupto 14.4Kbps, Data-Modemupto 14.4Kbps (ST75C540 only).
The DSP sofwareis extensively user configurable
allowing specific functionstobe supported like
Caller Identifier (CLID) and Second Call Waiting
Identifier (SCWID).
The DSP software includesa transparent mode
allowingthe host controllerto access directlythe
modem Analog Front End and the Audio AFE
throughthe dual Port RAM. Thisis veryusefulfor
hostprocessing modem solutions(orsoft modem)
wherethe modulation andthedemodulation (V.34,
V.90)are donebythe application main processor. transparent mode,the embedded DSP canbe
used simultaneously withthe same samples.
The transparentmodefor audio AFEis providedto
play audio filesorto record voice and/or audio.
1/84
CONTENTS Page DETAILED FEATURES.... ............... .......... ..... ..... ..... ..... 4
PIN DESCRIPTION.... ......................... ..... ..... ..... ........ 5
II.1 PIN CONNECTIONS.... ......................... ..... ..... ..... ........ 5
II.2 HOST INTERFACE. .......... ..... ............... .......... ............ 6
II.3 ANALOG INTERFACE. .......... ..... ..... .......... .......... ......... 6
II.4 GENERAL PURPOSEIO AND RELAY.... .... ...... ............... ........ 6
II.5 MISCELLANEOUS. .......... ..... ............... .......... ............ 7
II.6 POWER SUPPLY........................... ..... ................ ...... 7
III BLOCK DIAGRAMS.... ......................... ..... ..... ..... ........ 8
III.1 ANALOG INTERFACE. .......... ..... ..... .......... .......... ......... 8
III.2 INTERNAL BLOCK DIAGRAM. .......... .......... .......... ............. 8
ELECTRICAL SPECIFICATIONS. .................... .......... .......... 9
IV.1 MAXIMUM RATINGS...................... ..... ..... ................... 9
IV.2 RECOMMENDED OPERATINGCONDITIONS......... ..... ................. 9
IV.3 DIGITAL INTERFACE...................... ..... ..... ................... 10
IV.4 MODEM ANALOG INTERFACE.... ......... ................ ..... ..... .... 11
IV.5 AUDIO ANALOG INTERFACE. .......... .......... .......... ............. 11
IV.6 AC CHARACTERISTICS....................... .... ..... ................ 12
FUNCTIONAL DESCRIPTION. .......... .......... .......... ............. 13
V.1 SYSTEM ARCHITECTURE.... ......................... ..... ..... ....... 13
V.2 MODESOF OPERATION....................... .... ..... ................ 13
V.3 OPERATIONS........................ .... .... ................ ......... 13
V.3.1 Modem Transmitter Description.... ......... ................ ..... ..... .... 13
V.3.2 Modem Receiver Description....................... .... ..... ............. 13
V.3.3 Tone GeneratorDescription.... ......................... ..... ..... ....... 13
V.3.4 Tone Detector Description. .......... .......... .......... .......... ...... 13
V.3.5 V.21 Channel2 Flag Detector Description. .... ..... ........... .......... .... 13
V.3.6 HDLC Description........................... ..... ................ ...... 13
V.3.7 UART Description........................... ..... ................ ...... 13
V.3.8 DTMF Detector Description. .......... .......... .......... .......... ...... 13
V.3.9 Ring Detector........................ .... .... ................ ......... 13
V.3.10 VOCODER Description. .......... ..... ..... .......... .......... ......... 14
V.3.11 Voice Activity Detector (VAD)....................... .... ..... ............. 14
V.3.12 Telephony Functions.... ......................... ..... ..... ..... ........ 15
V.3.13 Low PowerMode........................... ..... ................ ...... 18
V.3.14 Reset.............. ........... ......... .......................... .... 18
V.4 MODEM INTERFACE...................... ..... ..... ................... 18
V.4.1 Analog Interface.... ......................... ..... ..... ..... ........... 18
V.4.2 GeneralI/O and Relay Interface.... ......... ................ ..... ..... .... 18
V.4.3 Crystal. ....................... ........................ ............... 19
V.4.4 Typical Application Schematic....................... .... ..... ............. 19
V.4.5 Host Interface........................ .... .... ................ ......... 19
USER INTERFACE. .......... ..... ............... .......... ............ 21
VI.1 DUAL PORT RAM DESCRIPTION. .................... .......... .......... 21
VI.2 COMMAND SET.... ......................... ..... ..... ..... ........... 25
VI.3 COMMAND SET SHORT FORM............ ........... .... ..... .......... 26
VI.4 STATUS- REPORTS...................... ..... ..... ................... 27
VI.5 DATA EXCHANGES.... ......................... ..... ..... ..... ........ 27
ST75C530- ST75C5402/84
VII COMMAND SET DESCRIPTION............ ........... .... ..... .......... 28
VIII STATUS DESCRIPTION....................... .... ..... ................ 43
VIII.1 COMMAND ACKNOWLEDGE AND REPORT...... .... ........... ........... 43
VIII.2 MODEM STATUS........................... ..... ................ ...... 44
TONE DETECTORS.... ......................... ..... ..... ..... ........ 53
IX.1 OVERVIEW. .......... ..... .......... .... ........... .................. 53
IX.2 DESCRIPTION. .......... ..... ............... .......... ............... 53
IX.3 EXAMPLE........................ ....... ................. ............ 59
PARALLEL DATA EXCHANGE.... ......... ................ ..... ..... .... 60
X.1 OVERVIEW. .......... ..... .......... .... ........... .................. 60
X.2 TRANSMIT BUFFER...................... ..... ..... ................... 60
X.3 RECEIVE BUFFER. .......... ..... ............... .......... ............ 61
X.4 INTERRUPTION.... ......................... ..... ..... ..... ........... 61
X.5 DATA FORMAT.... ......................... ..... ..... ..... ........... 61
X.6 FORM COMMAND. .......... ..... ............... .......... ............ 63
TRANSMITTING DATAIN PARALLEL MODE......... ..... ................. 64
XI.1 DESCRIPTION. .......... ..... ............... .......... ............... 64
XI.2 MODEM FLOW CHART.... ............... .......... ..... ..... ..... ..... 65
XI.3 HOST FLOW CHART...................... ..... ..... ................... 65
XI.4 ERROR DETECTION...................... ..... ..... ................... 66
XI.5 SYNCHRONOUS MODE....................... .... ..... ................ 66
XI.6 HDLC MODE.... .................... ..... ..... ..... ..... .............. 67
XI.7 UART MODE DESCRIPTION....................... .... ..... ............. 69
XII RECEIVINGIN PARALLEL MODE.... .......... ............... ..... ...... 70
XII.1 DESCRIPTION. .......... ..... ............... .......... ............... 70
XII.2 MODEM FLOW CHART.... ............... .......... ..... ..... ..... ..... 70
XII.3 HOST FLOW CHART...................... ..... ..... ................... 70
XII.4 ERROR DETECTION...................... ..... ..... ................... 71
XII.5 SYNCHRONOUS MODE....................... .... ..... ................ 72
XII.6 HDLC MODE.... .................... ..... ..... ..... ..... .............. 72
XII.7 UART MODE.... .................... ..... ..... ..... ..... .............. 74
XIII VOCODER DATA EXCHANGE.... ......... ................ ..... ..... .... 74
XIII.1 OVERVIEW. .......... ..... .......... .... ........... .................. 74
XIII.2 VOCODER BUFFER.... ......................... ..... ..... ..... ........ 74
XIII.3 TRANSMIT (DECODER)....................... .... ..... ................ 74
XIII.4 RECEIVE (CODER).... ......................... ..... ..... ..... ........ 75
XIV TRANSPARENT MODE DATA EXCHANGE....................... .... ...... 75
DEFAULT CALL PROGRESS TONE DETECTORS....................... .... 76
XVI DEFAULT ANSWER TONE DETECTORS......... ..... ............... ..... 76
XVII ELECTRICAL SCHEMATICS....................... .... ..... ............. 77
XVIII PCB DESIGN GUIDELINES.... ......................... ..... ..... ....... 78
XIX APPENDIXA: MODESOF OPERATION. .... ..... ........... .......... .... 78
PACKAGE MECHANICAL DATA. .................... .......... .......... 83
ST75C530- ST75C5403/84
- DETAILED FEATURESSingle Chip Fax ITU-T V.17, V.29, V.27ter,V.21 with Fax support V.17, V.29 (T104), V.27ter short trains,
V.33 half-duplex V.21 flag detection and4 tone detection during
high speed reception modes V.21 flag detection, DTMF detection and4
tone detection duringV.21 channel2 reception
modes Programmable call progress and call waiting
detection Parallel data handling HDLC and UART framing support 1700Hz and 1800Hz carrier Full implementationofthe V.17, V.33, V.29 and
V.27handshakes0to -15dBm programmable transmit power0to -47dBm receiver dynamic range(ST75C530) to-45dBmreceiverdynamicrange (ST75C540)
Full Duplex Data Modem ITU-T V.32bis, V.32 (14400, 12000, 9600, 7200,
4800bps)(*) Maximum roundtrip delay: 1.2s (satellite hops)
(*)Upto 10Hzof phaserollonfar end echo(*) ITU-T V.22bis, V.22 (2400, 1200bps)(*) V.32bis/V.32/V.22bis/V.22automode(*) ITU- V.23, V.21,bell 103 full-duplex,
Bell202 demodulator-10to -25dBm programmable transmit power -10to-38dBm receiverdynamicrange(*) HDLC and UART framing support Train basedon qualityline sampling(*)
(*) ST75C540 only
Digital Answering Machine Lowbit rate speech coder (4800bps) Variable playback speed (+50%to -50%) ARAMcompatibility (error correction) ADPCM32,24, 16Kbps Line echo cancellation Voice activity detector Concurrent DTMF and tone detection
Handset ModeRx andTx AGC versus line currentfor line
losses compensation comply with mostof
country regulations Dynamic limiterin transmit pathto prevent
distortion Two way conversation recording
Hands-free Mode Full duplex speakerphoneusing LMS adaptative
filtering including line echo cancellation and
acoustic echo cancellationRx andTx AGC versus line currentfor line
losses compensation comply with mostof
country regulations Dynamic limiterin transmit pathto prevent
distortion Loudspeakervolume control Two way conversation recording
Extended Modesof Operations Programmablering detection16 programmabletone detectors Tone and DTMF generators CallerID reception Transparent mode allowing direct transferof Mo-
dem AFE and audio AFE samplesto and from
host processorfor soft Modem applicationsand
sound files playing DTMF detection Wide dynamic range (>48dB)
Versatile Interfaces Parallel 128x 8-bit dual port RAM General purpose16I/O ports2 relay drive outputs Full diagnostic capability Dual 8-bit DACfor constellation display
Single5V Power Supply Typical active power consumption:
650mW (ST75C530),725mW (ST75C540) Low power mode< 30mW
ST75C530- ST75C5404/84
6667686970717273747527282930313233343536212223242577787980383940626364GIO10
DVDD4
DGND4
GIO07
GIO06
GIO05
GIO04
GIO03
GIO02
DVDD3
DGND3
GIO01
GIO00
RING
RELAY1
RELAY0
RGND
INT/MOT
SINTR
SCS
SPK1N
AGNDTA
VREFN
VREFP
SPK1P
VCM
AGNDRA
MIC1
MIC2
MIC3
RxA
AVDDM
AGNDM
TxA2
TxA1
EYEX
EYEY
DGND6
DVDD6
DGND1
DD1
SD0SD1SD2SD3SD4SD5SD6SD7
DGND2
DD2
SR/W
SDS
SA0SA1SA2SA3SA4SA5SA6
DDA
SPK2PSPK2NSPK3PSPK3NRESETTEST0EXTALLXTALLDV
DD5
DGND5XPLLCLKOUTGIO17GIO16GIO15GIO14GIO13GIO12GIO11
530
- PIN DESCRIPTION
II.1- Pin Connections
ST75C530- ST75C5405/84
II.2- Host InterfaceThe exchangeswiththe controlprocessor proceed througha 128x8 DUAL port RAMshared betweenthe
ST75C530/540andthe Host. The signals associated withthis interfaceare:
Pin Name Type DescriptionSD0..SD7 I/O System Data Bus. 8-bit data bus usedfor asynchronous exchanges betweenthe
ST75C530/540andthe Host throughthe dualport RAM. High impedance when exchanges
arenot active.
SA0..SA6 I System Address Bus.7-bit addressbusfor dualport RAM,IOand interrupt registers.
SDS (SRD) I System Data Strobe.In Motorola mode SDS initiatesthe exchange, active low.InIntel mode
SRD initiatesa read exchange, activelow.
SR/W (SWR) I System Read/Write.In Motorola mode SR/W definesthe typeof exchange read/write.InIntel
mode SWR initiatesa write exchange, activelow.
SCS I System Chip Select. Activelow.
SINTR OD System Interrupt Request. Opendrain.Activelow. Thissignal isasserted bytheST75C530/540
and negatedbythe host.
RESET I Reset. Activelow.
INT/MOT I Select Intelor Motorola Interface
II.3- Analog Interface
Pin Name Type DescriptionTxA1 O Transmit Analog Output1
TxA2 O Transmit Analog Output2
RxA I Receive Analog Input
SPK1P O Speaker Output1, (differential positive), mustbe connected through Amplifiertothe
loudspeaker.
SPK1N O Speaker Output1, (differentialnegative)
SPK2P O Speaker Output2, (differential positive), mustbe connected through Amplifiertothe Handset
loudspeaker.
SPK2N O Speaker Output2, (differentialnegative)
SPK3P O Speaker Output3, (differentialpositive)
SPK3N O Speaker Output3, (differentialnegative)
MIC1 I Microphone Input1
MIC2 I Microphone Input2
MIC3 I Microphone Input3
VCM I/O Analog Common Voltage (nominal+2.5V).Thisinputmustbe decoupled withrespectto AGND.
VREFN I Analog Negative Reference (nominal 1.25V). This input mustbe decoupled with respectto
VCM.
VREFP I Analog Positive Reference (nominal 3.75V).This input mustbe decoupledwith respectto VCM.
II.4- General PurposeIO and Relay
Pin Name Type DescriptionGIO[0,7] I/O General PurposeI/O Pins,canbe independently selectedas inputor output.
GIO[10,17] I/O General PurposeI/O Pins,canbe independently selectedas inputor output.
RELAY0,
RELAY1 Relay Outputs, Open Drain, Active Low.Cansink -10mAto RGND.
RING I Ring detectsignal. Activelow. Ifthe ST75C530/540isinlow powermode, alow level willawake
the chip. Thisinputisa Schmidt’s trigger.
RGND PWR Relay Digital Ground.To connectto GND.
- PIN DESCRIPTION (continued)
ST75C530- ST75C5406/84
II.5- Miscellaneous
Pin Name Type DescriptionEYEX O ConstellationX analog coordinate
EYEY O ConstellationY analog coordinate
XTAL O Internal Oscillator Output.Left openifnot used.
EXTAL I Internal Oscillator Input,or External Clock Input.
XPLL I Reservedfor futureuse, mustbe connectedto digital ground.
CLKOUT O Output Clock, EXTAL/2(not availableinlow power mode).
TEST0 I Testpinfor normal operation, mustbe connectedto digital ground.
Note: Thenominal frequencyofthe crystal oscillatoris 44.2368MHzwitha precision betterthan± 100ppm.
II.6- Power Supply
Symbol Nber ParameterDVDD 6 Digital +5V.
DGND 6 Digital Ground.
AVDD 2 Analog +5V.
AGND 3 Analog Ground.
- PIN DESCRIPTION (continued)
ST75C530- ST75C5407/84
ADC
MUTEDAC
LineHYBRID
TXA1
TXA2
RXA
ADC MIC3 MIC1 MIC2 SPK2
MUTE
SPK3
MUTE SPK1MUTE
[0..-30]dB
Step3dB
DAC
ST75C530/54075C
III- BLOCK DIAGRAMS
III.1- Analog Interface
III.2- Internal Block Diagram
DUAL
PORTRAM
GIO ANDRELAY
EYEDAC
PROM
INSTRUCTIONS
ANALOG
FRONT
END
TIME BASE
OSC
ST18932DSP
(24Mips)
RAM
6144 WORDS
ROM
16368 WORDS
AUTOTEST
INSTRUCTIONS
AUTOTEST
INSTRUCTIONS
EYEX
EYEY
XTAL
EYEY
CLKOUT
EXTAL
RING
RELAY0RELAY1Pins
Pins
GIO0[0..7]Pins
GIO1[10..17]
Pins22to29
SD[0..7]
Pins34to40
SA[0..6]
SINTR
Instruction
Bus
Data
Bus46
ST75C530/54075C
ST75C530- ST75C5408/84
- ELECTRICAL SPECIFICATIONSIV.1- Maximum Ratings (AGND= DGND= RGND=0V,all voltages with respectto0V)
Symbol Parameter Value UnitAVDD Analog Power Supply -0.3,6.0 V
DVDD Digital Power Supply -0.3,6.0 V Input CurrentperPin (except supplypinsand RELAY0and RELAY1) -10,+10 mA Output CurrentperPin (except supplypinsand RELAY0and RELAY1) -20,+20 mA
IO2 Output CurrentperPin RELAY0or RELAY1 (respectto RGND) -40,0 mA
VIA Analog Input Voltage -0.3, AVDD+0.3 V
VID Digital Input Voltage -0.3, DVDD+0.3 V
VIDGPIO Digital Input Voltageat GPIO 5.25 V
Toper Operating Temperature 0,+70 °C
Tstg Storage Temperature -40, +125 °C
Ptot Maximum Power Dissipation 1500 mW
Warning :Operationbeyond theselimitsmay resultin permanentdamagetothe device. Normal operationis notguaranted atthese extremes.
IV.2- Recommended Operating Conditions(AGND= DGND= RGND=0V,all voltageswith respectto 0V)
Symbol Parameter Min. Typ. Max. UnitVDD Supply Voltage 4.75 5 5.25 V
IDD Supply Current ST75C530
ST75C540
PDLP Low Power 30 mW Power ST75C530
ST75C540
VCM Common Mode Voltage Output (referto AVDD/2) -5 +5 %
ICM Common Mode Current (see Note1) 100 μA
Note1:DC currentonly.If dynamicload exists,theVCM outputmustbe buffered orthe performancesof ADCsand DACswillbe degraded.
ST75C530- ST75C5409/84
IV.3- Digital Interface(AVDD =DVDD=5V, AGND= DGND= RGND= 0V) except XTAL, EXTAL, RING.
Symbol Parameter Min. Typ. Max. UnitVIH High Level Input Voltage 2.2 V
VIL Low Level Input Voltage -0.3 0.8 V
VOH High Level Output Voltage (Iload= -2mA,Iload= -4mAfor SD[7..0]) 2.4 V
VOL Low Level Output Voltage (Iload= 2mA,Iload= 4mAfor SD[7..0]) 0.4 V
ILEAK Input Leakage Current -10 10 μA
IOL Low Level Output Current (except RELAY0and RELAY1,and SINTR)
IOH High Level Output Current (except RELAY0and RELAY1,and SINTR)2mA
IOZ GIO Three State Input Leakage Current (GNDIOZ SD Three State Input Leakage Current(GNDIOLRELAY Low Level Output Current RELAY0or RELAY1(VOL= 0.8V) -10 0 mA
CRYSTAL OSCILLATOR
VIH High Level Input Voltage 3.5 V
VIL Low Level Input Voltage 1.5 V High Level Input Current -20 μA Low Level Input Current 20 μA
RING(this input have hysteresis)
VIH High Level Input Voltage 2.4 2.8 V
VIL Low Level Input Voltage 1 1.2 V High Level Input Current -20 μA Low Level Input Current 20 μA- ELECTRICAL SPECIFICATIONS (continued)
ST75C530- ST75C540
10/84
IV.4- Modem Analog Interface
AVDD =DVDD =5V, Tamb =25oC
Measurement bandwidthisflat from 100Hzto 4800Hz ;Load impedance10kΩ, 20pF
For differentialoutput (TxA1/TxA2): 0dBr= 1.77VRMS 1kHz sinwave (equivalentto 5VPP).
For single input (RxA): 0dBr= 886mVRMS 1kHz sinwave (equivalentto 2.5VPP).
Symbol Pin Name Parameter Min. Typ. Max. Unit
Rxrin RxA Input Impedance 100 kΩ
Rxmac MaximumAC InputVoltage= 0dBr 2.5 VPP
Rxdc DC Reference Voltage 2.5 V
Rxsndr Signalto (Noise+ Distortion),at -6dBr 75 dB
Rxin Idle Noise -81 dBr
Rxov DC Offset Voltage (Input= VCM) -50 100 mV
TxAdrl TxA1/TxA2 Minimum Differential Load 10 kΩ
TxAcl Maximum Differential Load 20 pF
TxArout Output Impedance 100 Ω
TxAmac MaximumAC Differential Output= 0dBr 5 VPP
TxAdc DC Reference Voltage 2.5 V
TxAov DC Offset Voltage -200 200 mV
TxAsndr Signalto (Noise+ Distortion),at -6dBr 79 dB
TxAin Idle Noise -85 dBr
IV.5- Audio Analog Interface
AVDD =DVDD =5V, Tamb =25oC
Measurement bandwidthisflat from 100Hzto 4800Hz ;Load impedance10kΩ, 20pF
For differentialoutput (SPK1N/SPK1P,SPK2N/SPK2P,SPK3N/SPK3P): 0dBr= 1.77VRMS 1kHz sinwave
(equivalentto 5VPP).
For single input (MIC1, MIC2, MIC3): 0dBr= 886mVRMS 1kHz sinwave (equivalentto 2.5VPP).
Symbol Pin Name Parameter Min. Typ. Max. Unit
RArin MIC1,
MIC2,
MIC3
Input Impedance 100 kΩ
RAmac MaximumAC InputVoltage= 0dBr 2.5 VPP
RAdc DC Reference Voltage 2.5 V
RAdis Distortionat -6dBr 2 %
RAin Idle Noise -81 dBr
RAov DC Offset Voltage (Input= VCM) -50 50 mV
TAdrl SPK1N/SPK1P,
SPK2N/SPK2P,
SPK3N/SPK3P
Minimum Differential Load 10 kΩ
TArout Output Impedance 100 Ω
TAmac MaximumAC Differential Output= 0dBr 5 VPP
TAdc DC Reference Voltage 2.5 V
TAov DC Offset Voltage -200 200 mV
TAdis Distortionat -6dBr 1 %
TAin Idle Noise -81 dBr- ELECTRICAL SPECIFICATIONS (continued)
ST75C530- ST75C540
11/84
IV.6-AC ElectricalCharacteristics- ELECTRICAL SPECIFICATIONS (continued)
SCS
WRITE CYCLE READ CYCLE
Intel
mode 2 2
OUTIN67 14
SA[0..6]
SR/W
SDS
SD[0..7]
SINTR
GIO(out),
RELAY
GIO(in)
Motorola
mode
Number Description Min. Typ. Max. Unit Addressand Control Set-up Time 5 ns Addressand Control Hold Time 20 ns Write EnableLow State 45 ns Read EnableLow State 45 ns Access InhibitionHigh State 70 ns Data Set-up Time 10 ns Data Hold Time 5 ns GIO Output, Relay, SINTR Clear Delay 50 ns GIO Output Hold Time 0 ns Read Data Access Time 35 ns Data Validto Tristate Time 15 ns Data Hold Time 5 ns GIO Input Delay Time 40 ns GIO Input Hold Time 0 ns
ST75C530- ST75C540
12/84
- FUNCTIONAL DESCRIPTIONV.1- System Architecture
Thechipallowsthe designofa completeFAX,Data
Modem, Hands-Free Telephone and Answering
Machine system.A versatiledual port RAM allows easy interface with most micro-controllers.
V.2- Modesof Operation
Referto AppendixAfor Block Diagrams.
V.3- Operations
V.3.1- Modem Transmitter Description
The signal pulsesare shapedina dedicated filter
further combined witha compromise transmit
equalizersuitedfor transmission over stronglydis-
torted lines.3 differentcompromise equalizersare
available and canbe selectedby software.
V.3.2- Modem Receiver Description
The receiver section handlescomplex signals and
usesa fractionally spaced complex equalizer.Itis
ableto cope with distantmodem timing driftsupto-4 asspecifiedinthe ITU-Trecommendations.It
also compensatesfor frequency driftupto 10Hz
andfor phase jitterat multiple and simultaneous
frequencies.
V.3.3- Tone Generator Description
Fourtones canbe simultaneouslygeneratedbythe
ST75C530/540. These tonesare determinedby
theirfrequenciesandby theoutputamplitude level.setof specific commandsare also availablefor
DTMFgeneration.Anyof the4 tonegeneratorscan output independentlyeitheronthe Audio DACtheline DAC.
V.3.4- Tone Detector Description
During TONE (respectively TONECID) Mode six-
teen (respectively eight) tones canbe simultane-
ously detectedbythe ST75C530/540. Eachofthe
tonestobe detectedis definedbythe coefficientsa4th order programmableIIR. Detection thresh-
oldsare programmable from -51dBmupto -6dBm.
These primary detectors can detect toneupto
3.3kHz (sampling rate 7.2kHzinall modes). They
also havea programmable internal wiring feature
(see ChapterIX).all modes, except Handset(HANDSET)andFull
Duplex V.32bis/V.32/V.22bis/V.22 (Modem)
modes,4 additional tone detectors (eachof them
beinga4th order programmable IIR)are concur-
rently running.In Handset mode only2 additional
tone detectorsare available. Detection thresholds
are programmablefrom-51dBmupto -6dBm.This
secondary programmable detector can detect
tonesupto 1.8kHzby default set-up witha sam-
pling rateat 4.8kHz. But this4 additional tone
detectorscan also detect tonesupto 3.3kHz with samplingrateat 9.6kHz.In orderto avoid wrong
detectgion,relative detectgionis also provided.
V.3.5- V.21 Channel2 FlagDetector Description
Inall theReceiveFAXModes, includingV.21Chan-
nel2 Mode,the ST75C530/540 processesa V.21
Flag “7E” detector, eitherintheidle state,the train
sequenceorthe data mode. The detection timeis consecutive flagsto detect and1 byteto loose
the detection.
V.3.6- HDLC Descriptionall FAX Modes (MODEM), including V.21 Chan-l2 Mode, and also Full Duplex
V.32bis/V.32/V.22bis/V.22 (Modem) modes,a
HDLC framing and deframingis supportedbythe
ST75C530/540. The numberof transmitted flags
canbe programmed.
V.3.7- UART Description Full Duplex V.32bis/V.32/V.22bis/V.22 Modem
Modesand TONECIDV.23receivemode,a parallel
UARTis performedby the ST75C530/540. This
UART managethe Break signal eitherat thetrans-
mit andthe receivebit stream. The Data format
supportedare7 and8bitof Data; even, oddorno
Parity,1or2 stop bits.
V.3.8- DTMF Detector Description
ADTMFDetectoris includedin theST75C530/540, allows detectionof valid DTMF Digits.A valid
DTMF Digitis definedasa dual tone witha total
power higher than -43dBm,a duration higher than
40msanda differentialamplitude within±8dB.This
DTMF Detectoris enabledinall modes exceptin
Fax Modem, Data Modem and Handset modes.It also enabledin V.21 Channel2 Receive Mode.
The DTMF thresholds and duration canbe
changed from they default valueby overwriting
DSP’s RAM locations.In the default setup, this
detectoris compliant withthe NET4 standard.The
frequencydeviationcan bechangedby overwriting
the default DTMF’s filters coefficients.
V.3.9- Ring Detector
This detector detects RING signal from 15Hzto
68Hz,it canbe programmedto expandthe mini-
mum and maximum detection frequencyupto
12Hz(for min) and 144Hz (formax). The detection
timeis equalto one periodofthe ring signal, and
the loose timetothe minimum betweenone periodthe ring signal andthe inverseofthe minimum
frequency.
The associated STA_RING statusisas Figure1.
ST75C530- ST75C540
13/84
V.3.10- VOCODER Description
The Vocoder mode allowsthe implementationof answering machine function.In the CODER
modethe received samples from oneofthe two
analog inputs, Lineor Audio,are compressedby
the ST75C530/540 and written intothe dual port
RAM Vocoder Buffer (VOCxxx).Atthe same time
the ST75C530/540is lookingforan incoming
DTMFtone and4 different programmable tones.the DECODER modethe compressed samples
are read fromthe dual port RAM, decompressed
and transmittedto oneofthe two analog output,
Lineor Micx. The ST75C530/540 synthesisesan
estimationofits echo and subtractsit fromthe ceived signal.At the same time the
ST75C530/540is lookingforan incoming DTMF
tone and4 differenttones.
Two algorithmsof voice codingare implemented: Lowbit rate speech coder (4800bpsor 5300bps
with forward error correction). ADPCM (STproprietary algorithm)at32,24 and
16Kbps.thelowbit rate coder algorithmis selectedthe
ST75C530/540hasthe capabilityto slow downor
speedupthe DECODER flowupto ±50%. This
function allowsa quick message listeningif speedis used,oratthe oppositeif slow downis used, enhancementofthe voice intelligibility.
V.3.11- VoiceActivity Detector (VAD) CODER Mode,for bothof the Voice Coding
algorithms,a Voice Activity Detectoris imple-
mented while codingbythe ST75C530/540. The
STA_109bit and STA_109Fbit reflectthe stateof
the VAD. Afterthe CONF commandthe VADison
(assume voice). The default time-outto detectsi-
lenceis2 secondsand theset-uptimeto detectthe
voiceis 15ms. This VAD informationis also copied
intothe Receive Buffer Status Word MSB (VOC-
STA bit7). This detectoris fully programmablein
level sensitivity(downto -60dBm),hysteresis, and
various criteria. optional silence suppressoris implementedin
the Coder sectionto suppress long silenceinthe
incoming message. When enabled (CONF_SUP-
SIL equal1)ifa long silenceis detected (STA_109
equal0)the ST75C530/540stops generating Buff- Interrupts. After thatifa voiceis again detected
the ST75C530/540will resumethe Buffer Interrupt
mechanism.
RING
STA_RING
1/Fmax prog.Figure1- FUNCTIONAL DESCRIPTION (continued) Signal
STA_109
(or VOCSTAbit7)
Interrupt (IT1)
Figure2
ST75C530- ST75C540
14/84
V.3.12- TelephonyFunctions
ST75C530/540 telephony software provides both
handset and handsfree modes. ST75C530/540is
connectedto the phone line througha D.A.A.,
handset and loudspeaker are connectedto
ST75C530/540through amplifiers.
Thoughthe D.A.A. hasto comply with modem/fax
regulationsin mostofthe applications,the micro-
phone and the earphone amplifier gains willbe
adjustedin compliance withthe telephony regula-
tions. The softwareimplementedin ST75C530/540
allows functions suchas softclipping, AGCin both
modes,and fullduplex modein handsfree(see Fig-
ure3).
V.3.12.1- Handset Mode handset mode,allthe attenuations(_SPKGAIN,
_TXGAIN, _MIKGAIN) are from 0dBto -inf
(32768 steps). AGC and softclipping functionscan
beenabledand disabledbysoftware(seeFigure4).
DUAL
RAM
INTERFACE
ADC
MUTEDAC
LineHYBRID
TxA1
TxA2
RxA
ADCMIC3 MIC1 MIC2SPK2
MUTE
SPK3MUTE SPK1MUTE
[0..-30]dB
Step3dB
DAC
ATT_TX
CODER
HANDSFREE/
HANDSET
ALGORITHMS
ATT_MICTONE
GENERATOR
AGC
2TONE
DETECTORS
AGC
75C
Figure3: Handset/HandsfreeMode Operation- FUNCTIONAL DESCRIPTION (continued)
MIC2
SPK2_1
SPK2_2
_MIKGAIN
_SPKGAIN
Softclipping
AGC= F(ILINE)
RxA
DP_RING
TxA1
TxA2
_TXGAIN
AGC= F(ILINE)
75C
Figure4: HandsetMode
ST75C530- ST75C540
15/84
CharacteristicsSymbol Parameter Test Conditions Min. Typ. Max. Unit
Gtx Transmit Gain _MIKGAIN=7FFF,_TXGAIN=7FFF, AGC disabled
VMIC2= -21dBV
VMIC2= -9dBV
Ntx Transmit noise 2kΩ between MIC2and GND -73 dBmp
Mmic Microphone mute VMIC2= -21dBV 60 dB
VLpeak Transmit softclipping
levelon TxA1-TxA2
_MIKGAIN=7FFF,_TXGAIN=7FFF, AGC disabled
see Figure 3,VMIC2= -9dBV
2.5 Vpp
Dtx Transmit distortion _MIKGAIN=7FFF,_TXGAIN=7FFF, AGC disabled
see Figure 3,VMIC2= -9dBV Characteristics
Symbol Parameter Test Conditions Min. Typ. Max. Unit
Grx Receive Gain _SPKGAIN=7FFF,AGC disabled, VRXA=-16 dBV 6 dB
Nrx Receive noise -79 dBmp
Mrx Mute VRXA= dBV 60 dB
Dtx Receive distortion
(SPK2 output)
_SPKGAIN=7FFF,AGC Disabled, VRXA= -16dBV 2 %
AGC
The line current informationis coming fromthe
D.A.A.on DP_RINGpin (frequencycoded informa-
tion usingby examplea TS555 general purpose
timer).The AGChasa 6dB depth. Theattenuation
table canbe loadedto comply with each country
regulation. The default table hasthe followingval-
ues. The valueofthe AGC gainis appliedto both andRx path (see Table1).
The addressof the tableis giveninthe register
@_TABLE.
The table lengthis53. The AGCis enabled using
CONFor MODC command (see paragraph”VII-
COMMAND SET DESCRIPTION”.
Oncethe AGCis running,it ispossible tofreezethe
AGC gain withthe register AGC_FRZ.
Softclipping
The softclipping introducesa 12dB gain and hasa
18dB depth.
The softclipping valueis half digital range
(4000 Hex) (see Figure5).- FUNCTIONAL DESCRIPTION (continued)432MICX (mVRMS)3
(mVRMS) D (%)
VTxA1-TxA2(VRMS)
Distortion Softclipping and Distortion2
75C
Figure5: SoftclippingStatic Gain
Table1: AGC Gain versus Period Information
Period (ms) <9 10 10.8 11.6 14.5 13.3 14.1 15.5 16.6 17.5 18.3 19.1 20 >20
Table Index <13 13 14 15 16 17 18 19 20 21 22 23 24 >24
Gain (dB) 0 0.7 1.5 2.2 3 3.4 4 4.5 4.8 5.1 5.4 5.6 5.8 6
ST75C530- ST75C540
16/84
- FUNCTIONAL DESCRIPTION (continued)SPK1P
SPK1N
_SPKGAIN
RxA
TxA1
TxA2
ADAPTIVE
FIR
FILTER
MIC1
_MIKGAIN
ACOUSTIC
FILTER
ADAPTIVE
ATTENUATOR
NLMS
CONTROL
NLMS
ADAPTIVE
FIR
FILTER
AGC=F(IL)
_TXGAIN
Softclipping
AGC=F(IL) ADAPTIVE
ATTENUATOR
Figure6: HandsfreeMode: Full Duplex
V.3.12.2- Handsfree Mode
The handsfree usesa MIC1 anda SPK1as microphone and loudspeaker interface (see Figure6). Characteristics
Symbol Parameter TestConditions Min. Typ. Max. Unit
Gtx Transmit Gain _MIKGAIN=7FFF,_TXGAIN=7FFF ,AGC disabled,
VMIC1= -21dBV dB
Ntx Transmit noise 2kΩ between MIC1and GND -70 dBmp
Mmic Microphone mute VMIC1=-dBV 60 dB
Dtx Transmit distortion _MIKGAIN=7FFF,_TXGAIN=7FFF ,AGC disabled,
VMIC1= -9dBV Characteristics
Symbol Parameter TestConditions Min. Typ. Max. Unit
Grx Receive Gain _SPKGAIN=7FFF, AGC disabled, VRXA= -33dBV 24 dB
Mrx Mute 60 dB
Dtx Receive distortion
(SPK1 output)
_SPKGAIN=7FFF, AGC disabled, VRXA= -33dBV 2 %
AGC
The AGChasthe samebehavior asin Handsetmode. Furthermore,the maximum gain addedby AGCcan fixedby usingthe RX_GAINMAX and TX_GAINMAXregisters.
Softclipping
SeeFigure7.
System Stability
Parameter Test Conditions Min. Typ. Max. Unit
Loop attenuationinRx RxAto TxA1-TxA2 Speaker gainis 12dB, Mikegainis 14dB 20 dB
Loop attenuationinTx MICxto SPK1P-SPK1N Analogique sidetonenot used
(see DAA schematics) dBis possibleto add some gain switchingintheTx andRx path(to reducethe gainofthe loop)by using
the GAIN_RCV and GAIN_XMT registers.
ST75C530- ST75C540
17/84
- FUNCTIONAL DESCRIPTION (continued)2 103VSPK1 (VRMS)
Distortion Softclipping and Distortion
(mVRMS) D (%)32
VMIC2 (mVRMS)
Figure7: SPK1Distortion versus RxA
POWER SPEC1
POWER SPEC2
64Avg
64Avg
0%Ovlp
0%Ovlp
Ftop
Ftop
dBm
RMS
RMS
Vv2
FxdYO Hz 5k
LineTx
Speaker Output
Note: Acoustic echofrom speakerto microphoneinputwithno
local speech.Receiving speechonline input.
Figure8: Speakerand LineTx Power Spectrums
V.3.13- Low Power Mode
Sleepstatecanbe attainedbya SLEEPcommand.
Whenin sleepmode,the dual port RAMis unavail-
able andthe clocksare disabled.
When entering the low power mode, the
ST75C530/540stopsits oscillator,allthe peripher-
alsof theDSP coreare stoppedin orderto reduce
the power consumption. The dual port RAMis
made inaccessible.
The ST75C530/540canbe awakenedbya hard-
ware reset,a RINGsignalora dummywriteatany
locationinthe dual port RAM.
Thereisa maximum timeof 20msto restartthe
oscillator after wakingup andan additional 5ms
afterthe interrupttobe ableto accept any com-
mand coming fromthe host.
V.3.14- Reset
Aftera hardware reset,oran INIT command,the
ST75C530/540 clearsallits internal memories,
clearsthe whole dual port RAM and startsto initial-
izethe delta sigma analog converters.As soonas
these init ializat ions are completed, the
ST75C530/540 generatesan interrupt IT6 (com-
mandacknoledge) andis programmedto sendand
receive tones, thesample clockare programmedto
9600Hz.The total durationofthe reset sequenceis
about 5ms. After that timethe ST75C530/540is
readyto executecommands sentbythe hostmicro-
controller.The durationofthe resetsignalshouldbe
greater than 700ns.
V.4- Modem Interface
V.4.1- Analog Interface
Referto Block Diagramon page7.
V.4.2- GeneralI/O and Relay Interface pinsare dedicatedtothe generalI/O port. Two
arededicatedto Relaydriver.Theequivalentsche-
maticisas follows: see Figure9.D
GIO0[x]
IODIR0[x]
IODATA0[x]
(write)
IODATA0[x]
(read)D
RELAY[y]
IORELAY[y]
(write)
IORELAY[y]
(read) RGND
Figure9
ST75C530- ST75C540
18/84
V.4.3- Crystal
The crystal frequency mustbe 44.2368MHzfor
ST75C530and 49.152MHzfor ST75C540 withan
accuracybetterthat ±100 ppm. When usinga third
harmonic crystalthe schematic mustbeas follow:
see Figure10.
The crystal featuresare: third harmonic, parallel, load capacitance= 10pF,æ 100ppm from0oCto70oC,
-RS <50Ω, ATcut (example: SM55-10 MATEL).
XTALH3**
27pF
COG
0.82μH (ST75C530)
0.68μH(ST75C540)
10nF
10pF
COG
ST75C540 72
EXTALL XTALL
Wire wound inductor recommanded (Example: SIGMA-SC30)
Thrird harmonic (Example: MATEL-SM55-10)
XTALH3: 44.2368MHz (ST75C530)
49.152MHz (ST75C540)
75C
Figure10
V.4.4- Typical Application Schematic
The Figure11isa blockdiagramdesignedto allow
transmissionoffax signalsupto +0dBm and sine
waveupto +6dBmonthe telephone line.It allows
receptionof faxsignalsup to0dBmand sine waves
upto +6dBm.Figure12isa blockdiagramdesigned- FUNCTIONAL DESCRIPTION (continued)
-1/2
600Ω 1:1
Line
2.2nF
+8dB
-10dB
VCM
TxA1
TxA2
RxA
75C
Figure11
-1/2
600Ω 1:1
Line
2.2nF
0dB
0dB
VCM
TxA1
TxA2
RxA
Figure12 allow transmissionof Modem signalupto-
10dBm and receptionupto -10dBm.The OPAmps
are +12/0V powered. With this application sche-
matic theout ofbandtransmitspectrum(from4kHz 50kHz)is below -72dBm.
Figures13 and14are examplesofapplicationsche-
maticswhichrespectsgainvalue(respectivelyforfax
and voice application andfor Modem application)
andtheminimum differentialloadonTxA1andTxA2.
V.4.5- Host Interface
The host interfaceis seenbythe microasa 128x8
RAM, with additional registers accessible through 8-bit address space.A selectionPin (INT/MOT)
allowsto configurethe hostbusfor either INTELor
MOTOROLA type control signals.
ST75C530- ST75C540
19/84
- FUNCTIONAL DESCRIPTION (continued)GND
+12V
47.5kΩ
+6V+6V
470pF
18.2kΩ1%
18.2kΩ1%
470nF
470nF
270pF
24kΩ1%
TxA1
TxA2
1.2kΩ
33kΩ1%
24.3kΩ1% 470nF
560Ω
470nF
30kΩ1%
6.21kΩ1%
+6V
RxA
2.2nF
VCM
+6V +6V
22nF
+6V470nF
1:1* Insertionloss= 2.5dBbetween0and 3.4kHz
GND
+12V
Figure14: Data Mode
GND
+12V
47.5kΩ
+6V+6V
470pF
18.2kΩ1%
18.2kΩ1%
470nF
470nF
270pF
56.2kΩ1%
TxA1
TxA2
1.2kΩ
10kΩ1%
24.3kΩ1% 470nF
560Ω
470nF
30kΩ1%
6.21kΩ1%
+6V
RxA
2.2nF
VCM
+6V +6V
22nF
+6V470nF
1:1* Insertionloss= 2.5dB between0and 3.4kHz
+12V
GND
75C
Figure13: Fax Mode
ST75C530- ST75C540
20/84
- USER INTERFACEVI.1- Dual Port Ram Description
The dual port RAMis the standard interfacebe-
tweenthe host controller andthe ST75C530/540,
for either commandsor data. This memoryisad-
dressedthrougha 7-bitaddress bus. The locations
from $00to $3Fare RAM location,while locations
from $40to $60are control registers dedicatedto
the interrupt handling andthe generalIO port and
Relay output.
Severalfunctionalareasaredefinedinthe dualport
RAM mapping:the command area,the report area,the status area,the optional status area,the data buffer area,the interrupt control area,the generalI/O and Relay Output area.
VI.1.1- Mapping
VI.1.1.1- Command Area
The command areais located from $00to $04.
Address $00 holdsthe command byte COMSYS,
andthe next four locations holdthe parameters
COMPAR[0..3].The commandparametersmustbe
entered beforethe command wordis issued. Once
the command hasbeenentered,thecommandbyte
isresetandanacknowledge reportis issued.Anew
command shouldnotbe issuedbefore theacknow-
ledge counter COMACKis incremented.
VI.1.1.2- Report Area
The report areais located from address $05to
address $07. Location $05 holdsthe acknowledge
counter COMACK. Each timea commandisac-
knowledged,the report bytes COMREP[0..1](if
any)are writtenbythe ST75C530/540 into loca-
tions$06 and $07, andthe contentof COMACKis
incremented. Thisc ounter allows the
ST75C530/540to accurately monitor the com-
mand processing.
VI.1.1.3- Status Area
Thestatusareais located fromaddress$08to $0B.
TheerrorstatuswordSYSERRislocatedat address
$08.This errorstatuswordis updatedeachtimean
error condition occurs.An optional interruptionIT0
may additionallybe triggeredinthe caseofan error
condition. Locations$09 and $0A holdthe general
status bytesSTATUS[0..1].Themeaningofthebits
dependsonthe modeof operation,andis described Chapter VIII. The third byteat address$0B holds
the Quality Monitorbyte STAQUA.
VI.1.1.4- OptionalStatus Area
The user can program (throughthe DOSR com-
mand)the four locations STAOPT[0..3]ofthe Op-
tional Status Area ($0Cto $0F)forthe real time
monitoringof four arbitrary memory locations.
VI.1.1.5- Data Buffer Area
The data areais madeof four 8-byte buffers
(see ParagraphVI.1.3 “Host InterfaceSummary”).
Two are dedicatedto transmission and the two
othersto reception. Eachof the four buffersis
attachedtoa statusbyte.the meaningofthe status
byte dependsonthe selected formatof transmis-
sion. Within each buffer,D0 representsthe firstbit time.
VI.1.1.6- VOCODERBuffer Area
(VOCODERMode)
This areais madeofa 18+2 byte buffer.This buffer
containsthe VOCODER frame. The first18 bytes
VOCDATA containthe coded frame andthe other bytes VOCCORRthe Error correctionsbit (only
validinlowbit rate mode). theReceive Mode (CODER)the ST75C530/540
codesthe received samplesand writesthe corres-
ponding bytesinthe buffer.Ifthelowbit ratemode selected,the ST75C530/540computesthe Error
corrections2 bytes and writes theminthe buffer. the Transmit Mode (DECODER) the
ST75C530/540readsthe18 coded bytes decodes
them and sendsthe signal tothe analogoutput.In
the lowbit rate modeif the Error Correctionis
enabled, priorthe decoding,the ST75C530/540
reads the2 Error Correction Bytes and,if any,
correctsthe first18 bytes. mechanismof flagsto sharethe buffer access
betweenthe ST75C530/540andthe hostcontroller controlledbythe VOCSTAbyte:In CODER mode, whenthe ST75C530/540 has
finis-hed writingthe VOCDATA and VOCCORR
bytes,it writes $14in VOCSTA and generatean
InterruptIT1. The host must readthe Data buffer
then clearthe VOCSTAbyte.In DECODER mode, the host must feed the
VOCDATAand, optionaly,the VOCCORR bytes,
then write $14(iflowbit rate)or $12(if ADPCM) VOCSTA. The ST75C530/540 will readthe
VOCDATA and VOCCORR bytes, clear the
VOCSTA and generatean Interrupt IT1.Asi-
lence frame canbe generated,in eitherlowbit
rateor ADPCM mode,by writing00inall the
VOCDATAbuffer, includingthe Error Correction
Bytes VOCCORR.
ST75C530- ST75C540
21/84
VI.1.1.7- InterruptControl Area
The interrupt area, that start afterthe address $40
controlsthe behaviourofthe Interrupts mecha-
nism. Register ITSRCR definesthe sourceofthe
interrupt,the registerITMASK allows independent
enablingor disablingof anyof the interrupt’s
source, registers ITREST0to ITREST6 resetthe
corresponding interrupt source.
Theseregistersarenotaffectedbya INITcommand,
theyare onlyresetedbya Hardware RESETsignal.
VI.1.1.8- GeneralIO and Relay Output Areasetof5 registersis directly accessiblebythe
controllerto program the GeneralIO pins and
Relay Outputs (see Paragraph VI.1.3 “Host Inter-
face Summary”). Two registers IODIR0 andIO-
DIR1 definethe typeoftheIO pin, either Inputor
Output(0= input,1= output), and two registers
IODATA0 and IODATA1 definetheIOpin signals.
The fifth register definesthe Relay output signals.
Theseregistersarenotaffectedbya INITcommand,
theyare onlyresetedbya Hardware RESETsignal.
The generalIOare setupas input afterthe poweroran hardware RESET. The relay outputare
open after poweruporan hardware RESET.
VI.1.2- Interruptions
The ST75C530/540 can generate7 interruptsfor
the controller. The interrupt handlingis made withsetof registers located from $40to $5F.
The interruptions generatedbythe ST75C530/540
come from several sources. Once the
ST75C530/540raisesan interrupt,a signal (SINTR) senttothe controller. The controller has thento
processtheinterruptandclearit. Theinterruptsource
canbe examinedinthe interrupt source register
ITSRCR locateda $50. Accordingtothe ITSRCR
bits,the interrupt source canbe determined. Then
writinga zeroat oneofthe memory location$40to
$46 (Reset Interrupt Register ITRES[0..6])willre-
setthe corresponding interrupt (and thus acknow-
ledgeit). The sourceofthe interruptcanbe masked
globallyor individually using the Interrupt Mast
register ITMASK locatedat $4F.
The interrupt sourcesare:IT0: Error
This signifies thatan error has occurred andthe
error codeis availablein the error status byte
SYSERR. This byte canbe selectivelyclearedby
the CSE command.IT1: VOCODERBuffer
Each time the ST75C530/540 have codeda
frame (CODER Mode)or decodeda frame (DE-
CODER Mode)this interruptis generated.IT2:Tx Buffer
Each timethe ST75530/C540freesa databuffer,
this interruptis generated.IT3:Rx Buffer
Each timethe ST75C530/540 has filleda data
buffer,this interruptis generated.IT4: Status Byte
This signifies thatthe status byte has changed
and mustbe checkedbythe controller.IT5: Low Power Mode
TheST75C530/540hasbeenawakenedfromthe
low power modebya low levelonthe RINGpina dummy write issuedbythe host.IT6: CommandAcknowledge
This signifies thatthe ST75C530/540 has read
the last command enteredby the host, incre-
mentedthe command counter COMACK, andis
readyfora new command.
Note: Interrupt registersare cleared aftera Hard-
ware RESET. These registersarenot affectedby INIT Command.- USERINTERFACE (continued)
ST75C530- ST75C540
22/84
SINTR
(open drain)1234561234567
IT6: Command
ITREST6
(write only)
ITSRCR
(readonly)
ITMASK
(read write)
IT5:Low Power
ITREST5
(write only)
IT4: Status
ITREST4
(write only)
IT3:Rx Buffer
ITREST3
(write only)
IT2:Tx Buffer
ITREST2
(write only)
IT1: VOCODER
Buffer
ITREST1
(write only)
IT0: Error
ITREST0
(write only)
Figure15: Functional Schematic- USER INTERFACE (continued)
ST75C530- ST75C540
23/84
VI.1.3- Host InterfaceSummary
Address (hex) Description Size (Byte) Mnemonic
COMMAND AREA
$00 Command 1 COMSYS
$01-$04 Command Parameters 4 COMPAR[0..3]
REPORT AREA
$05 Acknowledge Counter 1 COMACK
$06-$07 Report 2 COMREP[0..1]
STATUS AREA
$08 Error Status 1 SYSERR
$09-$0A General Status 2 STATUS[0..1]
$0B Quality Monitor 1 STAQUA
$0C-$0F Optional Report 3 STAOPT[0..3]
DATA BUFFER AREA (FAX Modesand Data Modes)
$1C DataRx Buffer0 Status 1 DTRBS0
$1D-$24 DataRx Buffer0 8 DTRBF0[0..7]
$25 DataRx Buffer1 Status 1 DTRBS1
$26-$2D DataRx Buffer1 8 DTRBF1[0..7]
$2E DataTx Buffer0 Status 1 DTTBS0
$2F-$36 DataTx Buffer0 8 DTTBF0[0..7]
$37 DataTx Buffer1 Status 1 DTTBS1
$38-$3F DataTx Buffer1 8 DTTBF1[0..7]
VOCODER BUFFER AREA (Vocoder Mode)
$1C Vocoder Buffer Status 1 VOCSTA
$1D-$2E Vocoder Buffer Data 18 VOCDATA
$2F-$30 Vocoder Buffer Corrector 2 VOCCORR
INTERRUPT AREA
$40-$46 Reset Interrupt Register 7 ITREST[0..6]
$4F Interrupt Mask Register 1 ITMASK
$50 Interrupt Source Register 1 ITSRCR
GENERALIO AND RELAY
$60 I/O Direction0 1 IODIR0
$61 I/O Direction1 1 IODIR1
$62 I/O Data0 1 IODATA0
$63 I/O Data1 1 IODATA1
$64 I/O Relay Register 1 IORELAY
Note: Registers which addressis higheror equalto$40arenot affectedbyaINIT CommandoraLow Power wake-up.Theyare reseted
onlybya Hardware RESET.- USERINTERFACE (continued)
ST75C530- ST75C540
24/84
VI.2- CommandSet
The Command Set has the following attractive
features: user friendlywith easyto remembermnemonics, possibilityof straightforwardexpansionwith new
commandsto suit specific customer require-
ments, easyupgradeof existing softwareusing previous
modem based SGS-THOMSON products.
Thecommandset hasbeendesignedto providethe
necessaryfunctionalcontrolon theST75C530/540.
Each commandis classified accordingtoits syntax
andthe presence/absenceof parameters.Inthe
caseofa parametric command, parameters must
firstbe written intothe dual port RAM beforethe
commandis issued. Acknowledge and error report issuedfor each command entered.
VI.2.1- CommandSet Summary
VI.2.1.1- Operational Control Commands
INIT Initialize. Initialize the modem engine.
Setall parametersto their defaultvalues
and waitfor commandsof the control
processor. Non parametric command.
IDT Identify.Returnthe product identification
code. Non parametric command.
SLEEP Turn to low power mode, the
ST75C530/540 enters the low power
mode and stopsits crystal oscillatorto
reduce power consumption.In thismode
allthe clocksare stopped andthe dual
RAMis unreachable.
HSHK Handshake. Begins the handshake
sequence.The modemenginegenerates
allthe sequences definedinthe ITU-T
recommendations.A status report
indicatesto thecontrolprocessorthestatethe handshake. This command only
appliesto modes wherea handshake
sequenceis defined.A CONF command
must have been issued priortotheuseof
HSHK. Non parametric command.
STOP FAX Stop. Stop FAX Half-duplex
transmitter. Non parametric command.
RTRA Retrain. Begina retrain sequencein
V.32bis/V.32or V.22bis modesas
descr ibed in the ITU-T
recommendations(ST75C540 only).
SYNC FAXSynchronize.Start/Stopof FAXHalf-
duplex receiver. Parametric command.
CSE ClearStatusError.SelectivelyclearstheError
statusbyteSYSERR.Parametriccommand.
SETGN Set Gain. This command setsthe global
gain factor,whichis usedfor thetransmit
samples. Parametric command.
VI.2.1.2- Data Communication Commands
XMIT Transmit Data. Start/stop the
transmissionof data. Aftera XMIT
command,theST75C530/540sendsthe
data containedinits dual port RAM.
FORM Selectsthe Transmission Format. This
command configuresthe data interface
for bothre ceiver and transmitter
accordingtothe selected data format.
Parametric command (HDLC, UARTor
synchronous).
VI.2.1.3- Memory Handling Commands
MWI
MWLO
MemoryWrite Indirect
MemoryWrite Low Word
MemoryWrite. This commandis usedto
writean arbitrary 16-bit value intothe
writable memory location currently
specifiedbya parameter. Parametric
command.
MRI
MRLO
MemoryRead Indirect
MemoryRead Low Word
MemoryRead.Thiscommandallowsthe
controllerto read anyofthe ERAMor
CROM (S T75C530/540 memory
spaces) location without interruptingthe
processor.Parametric command. Complex Read. This command allows
the controllerto readatthe same time
the realandimaginary partofa complex
valuestored ina double ERAMor
CROM location. This featureis very
interestingfor eye pattern software
control andfor equalization monitoring.
This command insures thatthe real and
imaginary parts are sampledin the
memoryat the same time (integrity).
Parametric command.- USERINTERFACE (continued)
ST75C530- ST75C540
25/84
VI.2.1.4- Configuration Control Commands
ASEL Select the Analog path option, like
Microphone input, Speaker attenuation.
Parametriccommand.
CONF Configure.This command configuresthe
modem enginefor datatransmission and
handshake procedures(if any)in anyof
the supported modes. The transmission
parametersaresetto their default values
and canbe modified with the MODC
command. Parametric command.
MODC Modify Configuration. This command
allows modificationof someof the
parameters which have beensetupby
the CONF command.It can alsobe used alter the modeof operations (short
train). Parametric command.
DOSR Define Optional Status Report. This
command allowsthe modificationofthe
optionalstatusreport locatedin thestatus
areaofthe dual port RAM. One can thus
selecta particular parametertobe
monitored duringall modesof operation.
Parametriccommand.
DSIT Define Status Interrupt. This command
allows the programmingof the status
wordbit thatwill generatean Interruptto
the controller. Parametric command.
VI.2.1.5- Tone Generation Commands
TONE SelectTone.Programsthe tonegenerator(s)
forthe desired default tone(s). Additional
mnemonics provide quick programmingof
DTMF tonesor other currently used tones.
Parametriccommand.
DEFT Define Tone. Programs the tone
generator(s)for arbitrary tone synthesis.
Parametriccommand.
TGEN Tone Generator Control. Enablesor
disables the tone generator(s).
Parametriccommand.
VI.2.1.6- Tone Detection Commands
TDRC Read Tone Detector Coefficient. Reade Tone Detector Coefficient.
Parametriccommand.
TDWC Write Tone Detector Coefficient. Writee Tone Detector Coefficient.
Parametriccommand.
TDRW Read Tone Detector Wiring. Read one
Tone Detector Wiringco nnection.
Parametriccommand.
TDWW Write Tone Detector Wiring. Write one
Tone Detector Wiring connection.
Parametric command.
TDZ Clear Tone Detector Cell. Clear internal
variablesofa Tone Detector Cell.
Parametric command.
VI.2.1.7- MiscellaneousCommands
CALL Calla Subroutine. Calla subroutine with
one Parameter.Parametric command.
JSR Calla Low Level Subroutine. Callan
internal subroutine with one parameter.
Parametric command.
VI.3- CommandSet Short Form
CCI Command
Mnemonic Value Description
XMIT 0x01 Transmit Data
SETGN 0x02 Set Transmit Gain
SLEEP 0x03 Power Down theST75C530/540
HSHK 0x04 FAX Start Transmitter
RTRA* 0x05 Retrain(V.32bis/V.32andV.22bis)
INIT 0x06 Initialize (Software Reset)
CSE 0x08 Clear Error StatusWord
FORM 0x09 Define Data Format
DOSR 0x0A Define Optional Status Report
ASEL 0x0B Selectthe Analog Path Options
TONE 0x0C Generate Predefined Tones
TGEN 0x0D Enable Tone Generator
DEFT 0x0E Define Arbitrary Tone 0x10 Memory Read 0x11 Complex Read 0x12 Memory Write
DSIT 0x13 Define Status Interrupt
IDT 0x14 ReturnProduct IdentificationCode
JSR 0x18 CallaLow Level Routine
CALL 0x19 Calla Routine
TDRC 0x1A Tone DetectorRead Coefficient
TDRW 0x1B Tone DetectorRead Wiring
TDWC 0x1C Tone DetectorWrite Coefficient
TDWW 0x1D Tone DetectorWrite Wiring
TDZ 0x1E Tone DetectorClearCell
CONF 0x20 Configure
MODC 0x21 Modify Default Configuration
STOP 0x25 FAX Stop Transmitter
SYNC 0x26 FAX Synchronize Receiver
MRI 0x28 Memory Read Indirect
MRLO 0x29 Memory ReadLow Word
MWI 0x2A Memory Write Indirect
MWLO 0x2B Memory WriteLow Word ST75C540only.- USERINTERFACE (continued)
ST75C530- ST75C540
26/84
VI.4- Status- Reports
VI.4.1- Status
The ST75C530/540hasa dedicatedstatus report-
ing area locatedinits dual port RAM. This allowa
continuous monitoringofthe status variables with-
out interruptingthe ST75C530/540.
Thefirst status byte givesthe error status. Issuingan error status can alsobe flaggedbya mask-
able interruptforthe controller. The significationof
the error codesare givenin Chapter VIII.
The second and third status bytes givethe general
statusof the modem. These status includefor
examplethe ITU-T circuit status and other items
describedin Chapter VIII “STATUS DESCRIP-
TION”. These two status can generate, whena
changeoccurs,an interrupttothe controller; each
bitof the two byte word canbe masked inde-
pendently.
The forth byte givesin real timea measureofthe
receptionquality.Thisinformationmaybe usedbythe
controllerto monitorthe qualityofthe receivedbits.
Four other locations are dedicatedfor custom
status reporting. The controller can programthe
ST75C530/540fora real time monitoringofanyof
its internal RAM location. High byteorlow byteof
any wordcan thusbe monitored.
VI.4.2- Reports
The ST75C530/540 featuresan acknowledgeand
report facility. The acknowledgeofa commandis
monitoredbya counter COMACK locatedinthe
dualportRAM. Each timea commandis read from
the command area,the ST75C530/540will incre-
mentthis counter.For instance, whenaMR (Mem-
ory Read) commandis issued,the datais first
writteninthe report area, andthe counteris incre-
mentedafterwards. Thiswayof processinginsures
data integrity and gives additional synchronization
betweenthe controllerandthe data pump.
VI.5- Data Exchanges
The ST75C530/540 accepts many kindsof data
exchange:the defaultmode usesthe synchronous
parallel exchange. Other modes include HDLC
framing supportand UART. Detailed descriptionof
the Data Buffer Exchanges modesis availablein
the paragraphX.
VI.5.1- SynchronousParallel Mode
The data exchangesare made throughthe dual
port RAM andare byte synchronousoriented.The
double buffer facilitiesofthe ST75C530/540allow efficient bufferingofthe data.
VI.5.1.1- Transmit
The controller mustfirstfillat leastthe first buffer data(Tx Buffer0) withthebitstobe transmitted. orderto perform this operation,the controller
must first check theTx Buffer0 status word
DTTBS0.If this bufferis empty,the controllerfills
the data buffer locations(upto64 bits), and then
writesin DTTBS0the numberof bytes containedin
the buffer. The controller can then either proceed
withthe second bufferor initiatethe transmission
witha XMIT command.
TheST75C530/540copiesthe contentsof thedata
buffer and then clearsthe buffer status wordin
orderto makeit again available, then generatesan
IT2 interrupt. Thenumberof bytesspecifiedbythe
status wordis then queuedfor transmission. The
processgoeson with thetwobuffers untilan XMIT
command stopsthe transmission. Afterthe finish-
ing XMIT commandhas been issued,thelast buff-
ersare emptiedbythe ST75C530/540.
Errors occurwhenboth buffersare emptywhilethe
transmitbit queueis also empty. Erroris signalled
withan IT0interruptiontothe controller.
VI.5.1.2- Receive
Thecontroller shouldtake careof releasingtheRx
buffers beforethe Data Carrier Detect goes true.
Thisis madeby writing zerointheRx BufferStatus and1. The ST75C530/540 then fills the first
buffer,and once filled setsthe status word withthe
numberof bytes received and then generatesan
IT3 interrupt.It then takes controlofthe second
buffer and operatesthe same way. The controller
must checkthe statusof the buffers and empty
them. Oncethe data read, the controller must
releasethe used bufferand waitforthe next bufferbe filled.
Error occurs when both buffersare declared full,
and incomingbits continueto arrive fromthe line.
Erroris signaledbyanIT0 interrupt.
VI.5.2- HDLC Parallel Mode
This mode implements partofthe High Level Data
Link Control formats and procedures.Itis well
suitedfor error correcting protocolslike ECMor
FAXT4/T30 recommendations.Itsupportstheflag-
ginggeneration,16-bit FrameCheck Sequence,as
wellasthe Zero insertion/deletionmechanism.
VI.5.3- UART Parallel Mode
This mode implementa7or8bit data format,itis
well suitedfor CallerIDor Minitel applications.- USERINTERFACE (continued)
ST75C530- ST75C540
27/84
VII- COMMAND SET DESCRIPTION
Commandsare presented accordingtothe following form:
COMMAND Command Name Meaning COMMAND
Opcode Hexadecimaldigit XX XX X X
Synopsis Short descriptionofthe functions performedbythe command.
Parameters Field Byte Pos. Value Definition
Name X b..a*
Explanationofthe parameter
Defaultvalue
Field Nameofthe addressedbit field.
Byte Index(or addressinthe dual port RAM)ofthe parameter byte (from1to4).
Pos. Bit field position insidethe parameter byte. Can eitherbea single position (from0to7,0
being LSB)ora range.
Value Possiblevaluesforthebit(resp.bitfield).Rangemeansallvaluesareallowed.Astarmeansa default
value.Valuesareexpressedeitherundertheformofabit string,or underhexadecimalformat.
ASEL ASEL
Opcode: 0B 001 01 1
Synopsis Selectthe analog path options. This command selectthe Attenuation/Muteofthe outputs
TxA1/TxA2 and SPK1/SPK2/SPK3.This command select alsothe sourceoftheMic signal
MIC1/MIC2/MIC2andthe sourceofthe Line Signal RxA/MIC3.
Parameters Field Byte Pos. Value Definition
ASEL_ASPK1 1 7..4 0000*
Other
Infinity attenuation
30dB attenuation
27dB attenuation
3dB attenuation
0dB attenuation
Reserved
ASEL_MICSEL 2 1..0 00*
SelectRx inputas MIC1
SelectRx inputas MIC1
SelectRx inputas MIC2
SelectRx inputas MIC3
ASEL_LINESEL 2 2 0*
SelectRxAasline input
Select Mic3asline input
ASEL_ESPK1 2 3 0*
SPK1 output muted
SPK1 output normal
ASEL_ESPK2 2 4 0*
SPK2 output muted
SPK2 output normal
ASEL_ESPK3 2 5 0*
SPK3 output muted
SPK3 output normal
ASEL_MTXA 2 7 0*
TxA output normal
TxA output muted
CALL Calla Subroutine CALL
Opcode: 19 011 00 1
Synopsis CALL allowsto executea partofthe ST75C530/540firmware witha specific argument.
Parameters Field Byte Pos. Value Definition
C_ADDR_L 1 7..0 Low byteofthecall address
C_ADDR_H 2 7..0 Highbyteofthecall address
C_DATA_L 3 7..0 Low byteofthe argument
C_DATA_H 4 7..0 Highbyteofthe argument
This instruction canbe used with SGS-THOMSON Microelectronics Application Laboratory Supportfor
special applications developmentor debuggingneeds. Contact your local representative.
ST75C530- ST75C540
28/84
CONF Configurefor Operations CONF
Opcode: 20 1 00000
Synopsis CONF allowsthe complete definitionofthe ST75C530/540operation, includingthe modeof
operation (Tone, FAX Transmit, Voice Transmit,VoiceReceive, DTMF Receiver,...) andthe
Modemor VocoderParameters (Standard, speed,...). According withthe4 firstbitsofthe
CONF Parameterthe ST75C530/540isput intothe following modeof operation.
CONF_
OPER Mode Detectors
Tone(2) Tone(3) DTMF Ring VAD V.21 Flag CPT(5) Answ(6)
0000*
Other
TONE
TONECID(1)
DECODER
TRANSPARENT
CODER
ROOM-MONITOR
HANDSET/HANDSFREE
MODEM
Reserved(7)
Yes
Yes
Yes
Yes
Yes
Yes
Yes(4)
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes(4)
Yes
Yes
Notes: 1.This mode includes V.23/Bell202FSK Demodulatorand UART.This primary Tone Detectors allows Detectionof signalupto 3.3kHz. (SamplingRate 7.2kHz). ThissecondaryToneDetectorsallowsDetectionofsignalupto1.8kHz(withSamplingRate4.8kHz)orupto3.3kHz(withSamplingRate9.6kHz).The DTMF detectorandCall Progress Tone detector(CPT)are availableonly forV.21 Channel2. STA_CPT0,STA_CPT1and STA_CPT10in STATUS0. STA_CCITTand STA_ATin STATUS1.Not availablein V.32bis/V.32.
VII- COMMAND SET DESCRIPTION (continued)
ST75C530- ST75C540
29/84
Parameters Whenthe CONF_OPERis settoF, selectingthe Modem Modeof operation,theparameters
havethe following meaning:
Field Byte Pos. Value Definition
CONF_OPER 1 3..0 1111 Select Modem Mode
CONF_ANAL 1 4 0
Normal mode
Analogloop back (test mode only)
CONF_PSTN 1 5 0
PSTN (carrier detectsetto -43/-48dBm)
Leasedline (carrier detect -33/-38dBm)
CONF_AO 1 6 0
Answer mode
Originate mode
CONF_DTINIT
(onlyin tone mode)
Globalinitof secondary tone detector
Partialinitof secondary tone detector(8)
CONF_MODE 2 5..0 0
Other
Automode (V.32bis/V.32/V.22bis/V.22)(9)
Bell103(full duplex)
Bell 212A(full duplex)(9)
V.21(full duplex)
V.23(full duplex)
V.22(full duplex)(9)
V.22bis(full duplex)(9)
V.27ter
V.29
V.17
V.32(full duplex)(9)
V.32bis(full duplex)(9)
V.33 (half duplex)
V.21 channel2
Reserved
CONF_TXEQ 2 7..6 0 transmit equalizer
Transmit equalizer#1
Transmit equalizer#2
Transmit equalizer#3 (V.17/V.33/V.29/V.27ter)
CONF_CAR 3 0 0
1800Hz carrier (V.17/V.33 only)
1700Hz carrier (V.17/V.33 only)
CONF_TCM 3 1 0
Treillis codingnot allowed (V.32 only)
Treillis coding allowed (V.32bis, V.32)
CONF_SP0 3 7..4 xxx1
xx1x
x1xx
1xxx
1200bps allowed (V.22, V.22bis)(10)
2400bps allowed (V.22bis, V.27)(10)
4800bps allowed (V.32bis, V.32, V.27, V.29)(10)
7200bps allowed (V.32bis, V.29, V.17)(10)
CONF_SP1 4 2..0 xx1
x1x
1xx
9600bps allowed (V.32bis, V.32, V.29, V.17)(10)
12000bps allowed (V.32bis, V.17, V.33)(10)
14400bps allowed (V.32bis, V.17, V.33)(10)
Notes: 8. Withconf 80000000the coefficientsof secondarytone detectorsarenot initialized. ST75C540only.
10. V.22bis, V.22, V.32bisandV.32 modes ST75C540only.
VII- COMMAND SET DESCRIPTION (continued)
ST75C530- ST75C540
30/84
Parameters CODERand DECODER Modesthe VOCODER Modes, either CODERor DECODER, (CONF_OPER equals2or8)the
parametershavethe followingmeaning:
Field Byte Pos. Value Definition
CONF_OPER 1 3..0 - Define mode:see table above
CONF_CODE 3 0 0
Lowbitrate coded
ADPCM coded
CONF_VPF 3 1 0
Decoder post filteroff
Decoder post filteron(notin ADPCM)
CONF_VASP 3 3..2 00
ADPCM 32000bps
ADPCM 24000bps
ADPCM 16000bps
Reserved
CONF_EC 3 4 0
Line echo canceller disabled
Line echo canceller enabled
CONF_SRC 3 5 0
Coder sourceisline input
Coder sourceis audio input
CONF_SUPSIL 3 6 0
Coder silence supressor disabled
Coder silence supressor enabled
CONF_ERCOR 3 7 0
Lowbitrate decoder disable error correction
Lowbitrate decoder enable error correction
Parameters ROOM-MONITOR Modethe ROOM MONITOR Mode (CONF_OPER equals9)the parameters havethe following
meaning:
Field Byte Pos. Value Definition
CONF_OPER 1 3..0 1001 Define ROOM-MONITOR mode
CONF_EC 3 4 0
Line echo canceller disabled
Line echo canceller enabled
Parameters HANDSET/HANDSFREE Modethe HANDSET/HANDSFREE mode (CONF_OPER equalsC),the parameters havethe
following meaning:
Field Byte Pos. Value Definition
CONF_OPER 1 3..0 1100 Define HANDSET/HANDSFREE mode
CONF_INHINI 3 6 0
Initall telephony parameters
Disableinitof telephony parameters
CONF_HFREE 3 7 0
Handset mode
Handsfree mode
CONF_LEC 4 0 0
Line echo canceller enabled
Line echo canceller disabled
CONF_AEC 4 1 0
Audio echo canceller enabled
Audio echo canceller disabled
CONF_FULLD 4 2 0
Full duplex mode enabled
Half duplex mode enabled
CONF_SOFTRx 4 3 0
Softclipping enabledonRx
Softclipping disabledonTx
CONF_AGC 4 4 0
AGC active
AGC frozen
CONF_SOFTTx 4 5 0
Softclipping enabledonTx
Softclipping disabledonRx
VII- COMMAND SET DESCRIPTION (continued)
ST75C530- ST75C540
31/84
Complex Read CROpcode: 11
000 10001
Synopsis CR allowsthereadingofa complex parameter.Theparameterspecifiestheparameteraddress(for
thereal part:the imaginarypartis next location).CR returnsthe highbyte valueof bothrealand
imaginarypartofthe addressedcomplex parameter(see ChapterVIII“STATUS DESCRIPTION”).
Parameters Field Byte Pos. Value Definition
CR_ADDR_L 1 7..0 Low byteofthe 16-bit address
CR_ADDR_H 2 7..0 High byteofthe 16-bit address
CSE Clear Error Status CSE
Opcode: 08
000 01000
Synopsis CSEis usedto clearthe ST75C530/540 error status SYSERR byte.Itis also usedasan
acknowledgetothe error condition handler.
Parameters Field Byte Pos. Value Definition
ERR_MASK 1 7..0 Error mask.See report appendixfor detailed meaning
DEFT Define Arbitrary Tone DEFT
Opcode: 0E
000 01110
Synopsis DEFT programs oneofthe four tone generatorfor arbitrary tone generation.The parameterthe frequencyofthe generated tone expressedin Hertz between0 and 3600Hz.
Parameters Field Byte Pos. Value Definition
TONE_GEN_SL 1 1..0 Indexofthe tone generator (3..0)
TONE_FREQ_L 2 7..0 Low byteofthe frequency
TONE_FREQ_H 3 7..0 Highbyteofthe frequency (internally maskedwith0F)
TONE_SCALE 4 7..0 Amplitude scaling factor (high byte) givesthe nominal amplitude
DOSR Define Optional Status Report DOSR
Opcode: 0A
000 01010
Synopsis DOSR specifiesthe addressof the RAM variablestobe monitoredin the4 locations
STAOPT[0..3]ofthe dual port RAM.It also specifiesthe assignmentwithinthe4 locations.
Parameters Field Byte Pos. Value Definition
STA_OPT_ASS 1 1..0 0..3 Indexofthe STAOPT destination
STA_OPT_ADL 2 7..0 Low byteof source address
STA_OPT_ADH 3 3..0 Highbyteof source address
STA_OPT_HL 3 7 0
Selectlow byteof source
Select high byteof source
VII- COMMAND SET DESCRIPTION (continued)
ST75C530- ST75C540
32/84
DSIT Define Status Interrupt DSIT
Opcode: 13
000 10011
Synopsis DSIT specifiesthebit mask used withthe STATUS[0] and STATUS[1] byteto generatean
interruptIT4to controller. Each timeabit change happensinthe status words, assuming
the correspondingbit maskwillbe set,an interruptwillbe generated.
Parameters Field Byte Pos. Value Definition
STA_IT_MSK0 1 7..0 Status[0]bit mask pattern
STA_IT_MSK1 2 7..0 Status[1]bit mask pattern
Note: The defaultIT Statusis 0x3F forSTATUS[0]and 0xFFfor STATUS[1].
FORM Select TransmissionFormat FORM
Opcode: 09
000 01001
Synopsis FORM definesthe typeof transmission usedonthe line.
Parameters Field Byte Pos. Value Definition
X_SYNC 1 2..0 000*
Synchronous format
Transmit continous“1”(1)
HDLC framing
Transmit continous”0”(1)
UART
X_ANBIT 2 1..0 00Bitper characterBitper character
X_APAR 2 3..2 00 parity
Even parity
Odd parity
X_ASTOP 2 5 0 stopbit(1) stopbit(1)
Note: 1.Validonly when transmitting.
HSHK Handshake HSHK
Opcode: 04
000 00100
Synopsis HSHKis usedto commandthe ST75C530/540to beginthe transmithandshake sequence
processing. The progressofthe handshakeis reportedtothe control processor.
Parameter Non parametric command.
VII- COMMAND SET DESCRIPTION (continued)
ST75C530- ST75C540
33/84
IDT Identify IDT
Opcode: 14
000 10100
Synopsis IDTReturntheST75C530/540HardwareandSoftwarereleasenumber.SeeparagraphVIII.1.4.
Parameter Non parametric command.
INIT Initialization INIT
Opcode: 06
000 00110
Synopsis INIT forcesthe ST75C530/540to resetall parametersto their default conditions and restart
operations.
Parameter Non parametric command.
Note: This command makesa software resetofthe ST75C530/540andso cannothave theregular handshake protocol.It
doesnot incrementthe COMACK,neither generatean Interrupt.
JSR Calla Low Level Subroutine JSR
Opcode: 18
000 11000
Synopsis JSR allowsto executea partofthe ST75C530/540 firmware witha specific argument.
Parameters Field Byte Pos. Value Definition
C_ADDR_L 1 7..0 Low byteofthecall address
C_ADDR_H 2 7..0 High byteofthecall address
C_DATA_L 3 7..0 Low byteofthe argument
C_DATA_H 4 7..0 High byteofthe argument
This instruction canbe used with SGS-THOMSON Microelectronics Application Laboratory Supportfor
special applications developmentor debuggingneeds. Contact your local representative.
VII- COMMAND SET DESCRIPTION (continued)
ST75C530- ST75C540
34/84
MODC Modify Configuration MODC
Opcode: 21
001 00001
Synopsis MODC allowsthe modificationofthe parameters definedbythe CONF command.
Parameters Field Byte Pos. Value Definition
MODC_SDM 1 0 0
Normal data mode
Short datamode (e.g. TVR)(5)
MODC_DV21F 1 1 0
Normal V.21ch2(1)
Disable V.21ch2flag detector
MODC_DDTMF 1 2 0
Normal DTMF detector(1)
Disable DTMF detector
MODC_DTDT4 1 3 0
Normal secondary tone detector(1)
Disable secondarytone detector
MODC_DTDT16 1 4 0
Normal primarytone detector(1)
Disable primarytone detector
MODC_SH 1 6 0*
Normal training sequence
Short training sequence(2)
MODC_FS 1 7 0*
Secondary tone detector sampling frequencyis 4.8kHz
Secondary tone detector sampling frequencyis 9.6kHz
MODC_V22G(6) 2 1..0 00* guard tone
1800Hz guard tone (V.22bis/V.22)
550Hz guard tone (V.22bis/V.22)
MODC_FPT 2 3..2 00* echo protection tone
Long echo protection tone (180ms)(4)
Short echoprotection tone (30ms)(4)
MODC_NOTA(6) 24 0*
Answer mode: generate answer tonefor handshake
Originate mode:wait answertonefor handshake
Answer mode: donot generate answer
Originate mode:donotwait answer tone
MODC_NOSA(6) 26 0*
Cut answer tone whenreceivingAA (V.32bis, V.32)
Continue answertone when receivingAA.
MODC_NOQA(6) 27 0*
Enable V.32bis/V.32 autoretrainon quality.
Disable V.32bis/V.32 autoretrainon quality.
MODC_ADCFD 3 0..3 0000*
Other
Lowbitrate decoder voice frame duration 30ms (nominal)
Lowbitrate decoder voice frame duration 35ms (+16%)
Lowbitrate decoder voice frame duration 40ms (+33%)
Lowbitrate decoder voice frame duration 45ms (+50%)
Lowbitrate decoder voice frame duration 25ms (-16%)
Lowbitrate decoder voice frame duration 20ms (-33%)
Lowbitrate decoder voice frame duration 15ms (-50%)
Lowbitrate decoder pause
Reserved
MODC_COD 3 5 0
Lowbitrate coder disabled
Lowbitrate coder enabled(3)
MODC_LEC 4 0 0
Line echo canceller enabled
Line echo canceller disabled
MODC_AEC 4 1 0
Audio echo canceller enabled
Audio echo canceller disabled(3)
MODC_FULLD 4 2 0
Full duplex mode enabled
Half duplex mode enabled
MODC_SOFTRx 4 3 0
Softclipping enabledonRx
Softclipping disabledonRx
MODC_AGC 4 4 0
AGC active
AGC frozen
MODC_SOFTTx 4 5 0
Softclipping enabledonTx
Softclipping disabledonTx
Notes: 1.In themodes wherethey areactive. Shorttrain sequencemustbe precededbyatleastone successfullongtrain sequenceatthe samedatarate.For
V.17a successfullong trainat anydata ratemustprecededtheshorttrain. Only coderor decodercanbe enabledatthe sametime. Only when sending V.17,V.33,V.29or V.27ter. French Minitel Application(TVR: TeletelVitesse Rapide). ST75C540only
VII- COMMAND SET DESCRIPTION (continued)
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Memory Read MROpcode: 10
000 10000
Synopsis MRallowsthereadingofa 16-bitparameter.The parameterspecifiestheparameteraddress.
Parameters Field Byte Pos. Value Definition
MR_ADDR_L 1 7..0 Low byteofthe 16-bit address
MR_ADDR_H 2 7..0 High byteofthe 16-bit address
MRI Memory Read Indirect MRI
Opcode: 28
001 01000
Synopsis MRI allowsthe readingofa 16-bit parameter. The parameterspecifiesan indirect address.
Refertothe “RAM Mapping Application Note” (deliveredon request accordingto revision
number). The advantageto use MRI insteadofMRis thatthe Indirect Addressis constant
overthe different releaseofthe product.
Parameters Field Byte Pos. Value Definition
MRI_IADDR 1 7..0 Indirect Address
MRLO Memory Read Low Word MRLO
Opcode: 29
001 01001
Synopsis MRLO allowsthe readingof thememorylocation which addresscorespondsto thepreviousor MRI Absolute Adress minus1. This command mustbe precededbya MRor MRI
command. This command doesnot have any parameter. The double word readingis
executedbytheMRor MRI previous command. Memory Write MW
Opcode: 12
000 10010
Synopsis MW allowsthe writingofa 16-bit parameter. The parameter specifiesthe addressas wellthe valuetobe transferred.
Parameters Field Byte Pos. Value Definition
MW_ADDR_L 1 7..0 Low byteofthe 16-bit address
MW_ADDR_H 2 7..0 High byteofthe 16-bit address
MW_VALUE_L 3 7..0 Low byteofthe 16-bit value
MW_VALUE_H 4 7..0 High byteofthe 16-bit value
VII- COMMAND SET DESCRIPTION (continued)
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MWI Memory Write Indirect MWI
Opcode: 2A
001 01010
Synopsis MWIallowsthewritingofa 16-bitparameter.Theparametersspecifiesanindirectaddressaswell
asthe valuetobetransferred.Refertothe“RAMMappingApplicationNote”(deliveredonrequest
accordingtorevisionnumber).TheadvantagetouseMWIinsteadofMWisthattheIndirectAddress constantover thedifferentreleaseofthe product.
Parameters Field Byte Pos. Value Definition
MWI_IADDR 1 7..0 Indirect address
MWI_IVALUE_L 2 7..0 Low byteofthe 16-bit value
MWI_IVALUE_H 3 7..0 High byteofthe 16-bit value
MWLO Memory Write Low Word MWLO
Opcode: 2B
001 01011
Synopsis MWLO allowsthe writingofa 16-bit parameteratthe address definedbythe following MW MW Absolute Address minus1. This command mustbe followedbya MWor MWI
command.The double word writingis executedbythe MWor MWI following command.
Parameters Field Byte Pos. Value Definition
MWLO_VALUE_L 1 7..0 Low byteofthe 16-bit value
MWLO_VALUE_H 2 7..0 High byteofthe 16-bit value
RTRA (ST75C540 only) Retrain RTRA
Opcode: 02A
000 00101
Synopsis RTRAis usedto forcethe ST75C530/540to initiatea retrain sequenceora rate negotiation. MODC_NOQUAbitis set,the ST75C530/540will initiatea transmissionatthe maximum
speed definedbythe RTRAparameter, otherwiseitwill foundthe bestreliable speed basedthe qualityoftheline (withinthe RTRAallowed speed).
Parameters Field Byte Pos. Value Definition
RTRA_NEG0 1 0 0
Retrain (V.22bis, V.32, V.32bis)
Ratr negotiation (V.32bis, V.22bis)
RTRA_SP0 1 7..4 xxx1
xx1x
x1xx
1xxx
1200bps allowed (V.22bis)
2400bps allowed (V.22bis)
4800bps allowed (V.32bis, V.32)
7200bps allowed (V.32bis)
RTRA_SP1 2 2..0 xx1
x1x
1xx
9600bps allowed (V.32bis, V.32)
12000bps allowed(V.32bis)
14400bps allowed(V.32bis)
VII- COMMAND SET DESCRIPTION (continued)
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SETGN Set Output Gain SETGN
Opcode: 02
000 00010
Synopsis SETGNisa command which setsthe scaling factorofthe transmit samples.Itis usedfor
settingthe output levelorfor settingthelevelofthe tone generators.The gain valueis giventhe formofa2’s complement 16-bit value.
Parameter Field Byte Pos. Value Definition
GAIN_L 1 7..0 rangeFF* Low byteofthe 16-bitgain value
GAIN_H 2 7..0 range7F* High byteofthe 16-bitgain value
Example
Gain (dB) Gain (Hex) Gain (dB) Gain (Hex) Gain (dB) Gain (Hex) 7FFF -5 47FA -10 287A 7214 -6 4026 -11 2413 65AC -7 392C -12 2026 5A9D -8 32F5 -13 1CA7 50C3 -9 2D6A -14 198A
The multiplication factoris:10 (-1/20)= 0.89125for 1dB step.
SLEEP Turnto Sleep Mode SLEEP
Opcode: 03
000 00011
Synopsis SLEEPis usedto forcethe ST75C530/540to turntolow power mode.
Parameter Non parametric command.
Note: When receivingthiscommandtheST75C530/540will stopprocessingand socannot havethe regular handshake protocol.doesnot incrementthe COMACK,neither generatean Interrupt.
STOP FAX Stop Transmitter STOP
Opcode: 25
001 00101
Synopsis STOPis used,in FAX Modes,to forcethe ST75C530/540to turnoff the transmitterin
accordance withthe correspondingITU-T V.33/V.17/V.29/V.27recommendation.
Parameter Non parametric command.
Note: When receivingthis commandthe ST75C530/540willstop sending regular Data.This commandmustbe precededbya
XMITStop command.The ST75C530/540will waituntilallthe transmitbuffersare sentbefore startingtheStop sequence.
SYNC FAX Synchronizethe Receiver SYNC
Opcode: 26 0 1001 1 0
Synopsis SYNCis used,in FAX Modes,to forcethe ST75C530/540to Start/Stopthe receiverin
accordancewiththe corresponding ITU-T V.33/V.17/V.29/V.27recommendation.Assoonas
the ST75C530/540 receivesthe SYNC Startcommandit setsits receiverto detectthe FAX
synchronizationsignal.This commandisthe equivalent HSHK commandforthe receiver.
Parameters Field Byte Pos. Value Definition
RX_SYNC 1 0 0*
Stop receiver
Start receiver synchronization
VII- COMMAND SET DESCRIPTION (continued)
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TDRC Tone Detector Read Coefficient TDRC
Opcode: 1A
000 11010
Synopsis TDRC Read one Coefficientofthe selected Tone DetectorCell.
Parameters Field Byte Pos. Value Definition
TD_CELL 1 4..0 0..13 Tone detectorcell number
TD_C_ADDR 2 7..0 0..B(1)(1)
Biquad coefficient
Energy coefficient
Static level
Energy coefficient forrelative comparison
Gainfor relative comparison
The command answeris: Low Byteof Coefficient followedby High Byteof Coefficient.
Note1: Value30 and40of byte2 areavailableonlyfor secondarytone detector.
TDRW Tone Detector Read Wiring TDRW
Opcode: 1B
000 11011
Synopsis TDRW Read Wiringofthe selectedTone Detector Cell.
Parameters Field Byte Pos. Value Definition
TD_CELL 1 4..0 0..13 Tone detectorcell number
For primary tone detector
TD_W_ADDR 2 0 0
Other
Biquadand energy input
Comparator inputs
Reserved
The command answeris:If TD_W_ADDR=0: First Byteisthe Node Numberofthe Signal connectedto Biquadratic Filter input. Second Byteisthe Node Numberofthe Signal connectedtothe Energy estimator input.if TD_W_ADDR=1: First Byteisthe Node Numberofthe Signal connectedto Comparator Negative input. SecondByteisthe Node Numberof theSignalconnectedtothe Comparator Positive input.
For secondary tone detector TD_W_ADDRisnot defined. First byteis00if relative comparisonisnot mandatory,
First byteis01if relative comparisonis mandatory. Second byteisforthe configurationofthe secondary tone detector: configuration 1+1of secondary tone detectors, configuration1+1+2, configuration 1+1+1.
VII- COMMAND SET DESCRIPTION (continued)
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TDWC Tone Detector Write Coefficient TDWC
Opcode: 1C
000 11100
Synopsis TDWC Write one Coefficientofthe selected Tone Detector Cell.
Parameters Field Byte Pos. Value Definition
TD_CELL 1 4..0 0..13 Tone detectorcell number
TD_C_ADDR 2 7..0 0..B(1)(1)
Biquad coefficient
Energy coefficient
Static level
Energy coefficient forrelative comparison
Gainfor relative comparison
TD_COEFL 3 7..0 Low byteof coefficient
TD_COEFH 4 7..0 High byteof coefficient
Note1: Value30 and40of byte2 areavailableonlyfor secondarytone detector.
TDWW Tone Detector Write Wiring TDWW
Opcode: 1D
000 11101
Synopsis TDWW Write Wiringofthe selected Tone Detector Cell.
Parameters Field Byte Pos. Value Definition
TD_CELL 1 4..0 0..13 Tone detectorcell number
For Primary Tone Detector
Field Byte Pos. Value Definition
TD_W_ADDR 2 0 0
Other
Biquadand energy input
Comparator inputs
Reserved TD_W_ADDR=0 (Select Biquadand Energy Inputs)
Field Byte Pos. Value Definition
TD_W_ERN 3 0..3F Energy estimator signal input
TD_W_BIQ 4 0..3F Biquad filter signal input TD_W_ADDR=1 (Select Comparator Inputs)
Field Byte Pos. Value Definition
TD_W_CN 3 0..3F Negative comparator signal input
TD_W_CP 4 0..3F Positive comparator signal input
For Secondary Tone Detector
Field Byte Pos. Value Definition
TD_4DIFF 2 7..0 00
other
Relative comparisonnot enable
Relative comparison enable
Reserved
TD_4_CONF 3 7..0 0 Mandatory
TD_4_CONF2 4 7..0 C0
other
1+1 configuration
1+1+2 configuration
1+1+1+1 configuration
Reserved
VII- COMMAND SET DESCRIPTION (continued)
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TDZ Tone DetectorClear Cell TDZ
Opcode: 1E 0 0 11110
Synopsis TDZClearsall internalvariablesof one Tonedetectorcell includingFilter local variablesand
energy estimator.This command mustbe sent after changingcoefficientsofacellto avoid
instability.
Parameters Field Byte Pos. Value Definition
TD_CELL 1 4..0 0..13 Tone detectorcell number
TGEN Enable/Disable Tone Generators TGEN
Opcode: 0D
000 01101
Synopsis Enableor disable oneofthe four tone generator, definethe outputofthe tone generator
either Lineor Audio.
Parameters Field Byte Pos. Value Definition
TONE_0_ENA 1 0 0*
Generator#0 disabled
Generator#0 enabled
TONE_1_ENA 1 1 0*
Generator#1 disabled
Generator#1 enabled
TONE_2_ENA 1 2 0*
Generator#2 disabled
Generator#2 enabled
TONE_3_ENA 1 3 0*
Generator#3 disabled
Generator#3 enabled
TONE_0_OUT 1 4 0*
Generator#0 output toline
Generator#0 output toaudio
TONE_1_OUT 1 5 0*
Generator#1 output toline
Generator#1 output toaudio
TONE_2_OUT 1 6 0*
Generator#2 output toline
Generator#2 output toaudio
TONE_3_OUT 1 7 0*
Generator#3 output toline
Generator#3 output toaudio
VII- COMMAND SET DESCRIPTION (continued)
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TONE Predefined Tones TONE
Opcode: 0C
000 01100
Synopsis TONE programsthe tone generatorforthe predifined tones. The tone generator#0 and
eventualy#1are reprogrammed with thiscommand. The tone generator#0 and eventualy
the#1are enabled. Usinga valuenotinthe following tablewill disable tone generator#0
and#1.
Parameters Field Byte Pos. Value Definition
TONE_SELECT 1 5..0 0
DTMF digit0
DTMF digit1
DTMF digit2
DTMF digit3
DTMF digit4
DTMF digit5
DTMF digit6
DTMF digit7
DTMF digit8
DTMF digit9
DTMF digitA
DTMF digitB
DTMF digitC
DTMF digitD
DTMF digit*
DTMF digit#
Answer tone 2100Hz
Tone 1650Hz
Tone 2225Hz
Tone 1300Hz
Tone 1100Hz
TONE_OUT 1 7 0
Outputonline
Outputon audio
XMIT Start/stop Transmission XMIT
Opcode: 01
000 00001
Synopsis XMIT startor stopthe transmissionofthe TransmitData.
Parameters Field Byte Pos. Value Definition
TX_START 1 0 0*
Stop transmission
Start transmission
VII- COMMAND SET DESCRIPTION (continued)
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