Appendlx B - Am7911 versus Am7910 FSK Modems Tho Am7g11 Modem has Ihe same basic sl.c4ure and tunclion a5 the Am7910. The devices dit~cr only in the speCifications tor carrter detect and handshake limin9 necossary to support their intended applitalions Am7910 Silchod-ne Iwork applications Am791 1 Leasea-line. Telex and Video lext app,ications Hardware Ditterence Ttie on~y hardware or hook-up di~crence between Ihe Am7910 ar:d ~6m7911 is Ihe resistor requ~rOd between CAP' and CAP2' 100 ohms fo, the Am7910 910 ohms for Ihe Am7911 MC4 I MC3MC2 j MCl I MCo | O, O O O ' O 1 o . 0 0 0 1 . O ' O O j 1 1 0 1 o ! o ~ O ! 1 , 1 o ~o 1 ~ o o 0 1 0 j 1 0 1 ! 0 1 0 1 1 1 1 0 O O 1 ' 1 ' 1 1 o 1 1 O O O 1 0 i ~O I O I 1 ~O ' 1 O ' ~O I 0 1 1 o I ~I ~ j O ~1 j 1 1 0 1 o 0 1 ~1 0 1 C . 1 1 i 1 0 0 1 1 , 1 i 1 ' 1 , O i O ~O O . 1 1 0 1 0 0 1 j 1 ; 0 1 0 , 1 i O 1 0 0 ' 1 . 1 i 1 1 0 j 1 1 0 0 1 t 1 0 1 1 1 o , 1 i 1 ; 0 1 1 1 1 j O , 1 1 0 . 1 1 1 ! 1 1 1, o o ~ o j 1 ~ 1 1 ~' O . 1 1, j 1 ~ 'O i 1 O t 1 0 1 1 . 1 ~, 1 ~ ' O i O . I 1 ~ 1 1 ! O ' 1 Reserved ! 1 ~ 1 1 ~ 1 o . ~ 1 ~ 1 ' 1 i . . . ~U~ lo 150 baud backvrard channel is ava~la~le A summary o! the charac~erislics o, the Am7911 that are ditter- ent than ihe Am r 910 are as follo~vs; Reduced Ca. rier Detect response time Red-uced R rs to CTS response iime ReduCed Squelch lime for 1200bps modems Two new moaeS for Bell 202 with 150bps back channel Three new modes for V 23 Y'hh sch turn-oR tone The V.23 modes include 1 50bps back channel The Am7s11 supports the CCI~ R.20 recommendations for Telex ctpplicat~ons Ihe lollwing tables and ligurc-s tor the Am7911 represent Ihe dala sheet variations Irom the Am7910 shown in Appendr' A. TA8LE 1. Am7911 MODE SELECTIABLE Ben 103 Orig~nate 300bps {ull dup!ex Bcll 103 Answer 300bps full duplex 3ell 2021200bps ha!t duplex wi~h 5bps back cha:,nel Bell 202 120bps \'ith amplitude equalizer and SbpS back channel CCITT V.21 Orig 300bps loll d'~p~ex CCITT V.21 Ans 300bps tull doplex CCITT V.23 Mode 2 1200bp$ hait duplex CCITT V 23 Nlode 2 wi~h amplitude eq~alizer 120bps halt duplex. CCITT V 23 Mode 1 600bps halt duplex ResOrved 9eli 202 1200bps with 150bps back channel Bell 202 1200bps `~'ith amptitude ecDalize! and 150bps back channel CCITT V 2q Mode 1 600bps wi~h soN lurn-off Rese~`cd CC'TT V 231~,odc 2 1200bps with Sott iarn~cH. CCI1~T ~r 23 Mcde 2 ,200bps wilh ampl~tude e~ual~zer and sott turn-at1' : Bell 103 Orig loopback Bel' lu3 Ans loopback Bell 202 Main !oopback Be!l 202 wi~h amplitude equatizer loopback CCITT V 21 Orig icopback ~CiTT V 21 Ans loarback CCITT V 23 Mode 2 main loopback CCITT V.23 Mode 2 with ampillude equalizer loopback CCITT V.23 Mode 1 main loopback CCtTT V 23 Back loopback Bell 202 150bps Back loopback Am791 1 FSK MODEM woRLD.cHIprM Advanced Micro Devices DISTINCTIYE CHARACTERISTICS Compiete rSK MODEM in a 28-pin package - just add line interface Compatible with Beil 103/113/108, Bell 202, CCITT V.21, CCITT V 23 sp~cifications Mode seler table 5 or 150 baud backward channel /or Bell 202 Up to 150 baud on V.23 backward channel CCITT V.23 modes ~yith optional sott carner turn ~ ot' leature Fast response times tor ieased-line networks No external tiltering required All diglal signal pro~essing, digital fillers and ADC/DAC Included on-chip Includes essential RS 232/CCITT V.24 handshake signals 1 - GENERAL DEscRlpnoN The Am7911 is a single-chip asynchronous Frequency Shitt Keying (FSK) voiceband modem inlended for use in leasod line applications. It is pin selectable for baud rates oi 300. 600 or 1200 bits per second and is compatible with thc applicable Bell and CCITT recommended slandards for 103/113!106, 202, V.21 and V.23 type modems. Flve mode controi lines select a deslred modem configuration, tor Bell 202 applicabons, the Am7911 provides a 1sobps back channel in audition to the standard 5bps channel, and for V.23 up to 1sobps back channel operation is possible Digital signal processsing techniques are empioyed in the Am7911 {o perform all major functions such as modulalion demodulation and tiltering. The Am7911 contains on-chip analog-to-digital and digital-to-anatog converter circuits to minimize Ihe external components in a syslem This device includes the essential RS-232iCCITT V 24 terminal control siguals with TTL lovels. Clocking can be generated by attaching a cnystal to the internal crystal oscillator amplilier or by applying an ex- ternal cioch signal. A data access arrangement (DM) or acoustic coupler musl provide the phone line interface externally. The Am7911 is labricated using N-channel MOS technol- ogy in a 28-pin pachage All the digital input and outpsut signals (except the external cioch sigual) are TTL compati- ble Power supply requirements are ~ 5 volts. F gure 2. Block Diagram cAP ~C&P, C~ R!CEIVED 0 CA~IER t0,~4,~ J~LTRANSVITTED,C ,p~5~:TTLR FAC5 , : ~ _ ~~ 1 ~cOc~ _ LiC, C - llAfACF COATROL = jJAl~4,bAL c ~ arADY _ ~- _ _ ~.~ m _ 5I F V O ~L LACM