ID-880H/E880 SERVICE MANUAL

4-4 CPU (MAIN UNIT; IC25) PORT ALLOCATIONPINNo.LINE NAME DESCRIPTION I/O3 AN4 DA_SEL5 MM_MUTE6 DCONT81200_9600SELAudio response select signal."H"=FM mode."L"=DV mode.Cut-off frequency shifting signal to theHPF (IC48).MIC mute signal to the MIC mute switch(IC30)."H"=MIC mute.ALC amplifier control signal to the AFswitches (IC29 and IC52)."H"=ALC amplifi er ON.Baud rate select signal to the packetmodulation select switch (IC30).9 P_PTT Packet PTT detect signal. I10 P_SQL Packet squelch control signal. O11 MIC_SENCMicrophone sensitivity select signal."H"=High sensitivity.O16 DADJSELModulation mute signal to the digitalmodulation switch (IC34).17 MOD_DAModulation line switching signal to theMOD mute switches (IC9 and IC67). O"H"=Modulation enable.22 PLLSTB Strobe signal to the PLL IC ( IC14). O23 AMCAM-demodulator circuit control signal."L"= While receiving in AM mode (AMmodulatorand AGC circuits areOactivated).24 DTCS_SELTone filter switching signal to theLPF (Q100)."H"=DTCS mode.O"L"=CTCSS mode.25 R5CRX circuits control signal."H"=RX circuits is activated.O26 WN_SEL2nd IF filter (Wide/Narrow) togglingsignal."H"=Narrow.O"L"=Wide.28 UTX_CTransmitting control signal to the UT8 lineregulator (Q13, 17).O"H"=While transmitting in UHF band.29 VCO_SHIFTVCO oscillating frequency shift signal tothe VHF VCO switch (Q110).O32 PLLCK Clock signal to the PLL IC (IC14). O33 PLLDATA Data to the PLL IC (IC14). O34 UNLOCK PLL unlock signal from the PLL IC ( IC41). I35 MMUTEModulation mute signal to the MOD muteswitch (Q64).O"H"=Modulation muted.36 VTX_CTransmitting control signal to the VT8 lineregulator (Q12, 15).O"H"=While transmitting in VHF band.37 PLLSWLock-up time control signal to the loopfi lter.O"H"=Fast lock-up time.38 UVCO_SELVCO power control signal to the VCOselect switch (Q65, 68).O"L"=UHF VCO is activated.39 VVCO_SELVCO power control signal to the VCOselect switch (Right band VHF; Q65, 68). O"H"=VHF VCO is activated.48 D5VCPower control signal for the digitalconverter circuits.O52 AFFIL_SELSwitching signal to the AF fi lter (Q47)."H"=FMO"L"=AM/DV55 DTCS DTCS and CTCS signals. OOOOOOPINNo.LINE NAME DESCRIPTION I/O56 DTMFBeep, DTMF and european tone (E880only) signals.O57 MIC_SEL Connected microphone detect signal. I62 MICUD[UP]/[DWN] key input from connectedmicrophone (HM-154).I63 AMRSSIInputs RSSI signal (for AM mode) fromthe AGC line controller (Q44).I64 RSSIWhile receiving; inputs RSSI signal fromthe IF IC (IC15).I65 IDETCurrent level from the current detector(IC55, D163).I66 HVin Divided voltage of the HV line. I69 WXALTDemodulated Weather alert signal fromthe AF fi lter. ([USA] only)I70 DTCS_INDemodulated CTCSS and DTCS signalsfrom the CTCSS fi lter (Q41).I71 TEMPTransceiver's internal temparature fromthe thermal detector circuit (R509).I76 SCLI/O port for clock signal to the EEPROMI/O(IC22).77 AF_VOL_CKSerial clock signal to the electric volumeIC (IC66).O78AF_VOL_DATA80 PWRData signal to the electric volume IC(IC66).Power control signal to the PWR controller(Q82)."H"=While the transceiver power is ON.82 SDA Data signal to the EEPROM (IC22). I/O85 MIC_PTTInput port for [PTT] key on the connectedmicrophone.I101 SQL Noise signal from the IF IC (IC15). I103 CL_SFT1 Clock frequency shift signal. O107 ACQ ACQ signal to the modem IC (IC1012). O108 98_DATACommunication signal to the connectedI/Omicrophone (HM-133).109 TXDT TX data (DV) to the modem IC (IC1012). O110 TXCKTX clock signal (DV) to the modem IC(IC1012).O111 RXDT RX data (DV) to the modem IC (IC1012). I112 RXCKRX clock signal (DV) to the modem IC(IC1012).I113 AMBERES Reset signal to the DSP CODEC (IC1006). O114 AMBECLK Clock signal to the DSP CODEC (IC1006). O115 AMBEEPREPR (Encode Packet Ready) signal to theDSP CODEC (IC1006).O116 AMBESTB Strobe signal to the DSP CODEC (IC1006). O122 RX_DATA Data lines for the control unit. I123 TX_DATA Data lines for the control unit. O127 TX232 Data bus for RS-232C communication. O128 RX232 Data bus for RS-232C communication. I129 DA_CK Serial clock signal to the D/A converter. O130 DA_DATA Serial data to the D/A converter. O131 AMBETXD AMBE RX signal. I132 AMBETRD AMBE TX signal. O134 DA_STB Strobe signal to the D/A converter. O142 MOD_MUTE Packet modulation mute signal. O143 FIL1(143pin)144 FIL2(144Pin)AF fi lter circuits control signals.OOO4 - 7