Icom IC-M604A Service Manual - Page 15

4-7-3 CPU (LOGIC BOARD; IC1) Pin Port number name Description Input port for PLL unlock signal from 40 UNLK the PLL IC (MAIN unit; IC12, pin 7). High : While PLL is unlocked. I/O port for the data signals to the 41 EDATA EEPROM (IC4, pin 5). 28 ECK Outputs a clock signal to the EEPROM (IC4, pin 6). Input port for the decode signal for 34 DE.C3 channel 70 receiver. 38 DEC1 Input port for the ATIS/DSC decode signals. 110 BEEP Outputs beep audio signals. 58 DATAMC I/O port for the cloning data from the transceiver. 59 DATACM I/O port for the cloning data to the transceiver. I/O port for the communicating signal 63 DATAMH1 from the transceiver to the micro- phone (HM-162/1). I/O port for the communicating signal 64 DATAH1M from the microphone (HM-162/1) to the transceiver. 66 DATANM I/O port for the GGA signals 69 DATAMN I/O port for the NMEA data. 70 PDATA Outputs a data signal to the PLL IC (MAIN unit; IC12, pin 5). Outputs a clock signal to the PLL IC 71 PCK (MAIN unit; IC12, pin 4). Outputs the voice scrambler unit 6 OPTIN (UT-112) detecting signal. Low : While UT-112 is connecting. 92 RMUTE Outputs RX muting signal. High : While RX signal is muting. 93 TMUTE Outputs transmit mute signal. High : While TX muting. 94 SEND Outputs T8 regulator control signal. High: While transmitting. Output port for RF output power (High 96 H/L or Low) select signal. Low : While Low power is selected. Output RX attenuator control signals. ATT level OFF ON (1) ON (2) MAX. 97 ATT2C ATT1C 1 1 0 1 98 ATT1C ATT2C 1 0 1 1 103 WXDEC Input port for the weather alert signal. Input port for the FM IF IC (MAIN unit; 104 SQL IC1, pin 14)'s noise amplifier detect- ing signal. Pin Port number name Description Input port for the low-battery detecting 105 LBAT signal. Low battery indicator appears when the battery becomes less than 2.58 V 106 TXDET Input port for transmit detecting signal. 107 TEMP Input port for the indide temperature detecting signal. 111-114 DIAL1- Input ports for the dial data signals. DIAL4 Input port for the HM-136's PTT but- 115 PTT ton detecting signal. Low : While PTT button is pushed. Input port for the microphone hanger 26 HANG detecting signal Low : The microphone on hook. 117 DSC Outputs ATIS/DSC encode signals. 120 SCON Outputs the voice scramber unit (UT-112) control signal. 121 OPSTB Outputs a strobe signal to the voice scrambler unit (UT-112). 124 DASTB Outputs a strobe signal to the PLL IC (MAIN unit; IC12, pin 3). 125 PSTB Outputs a strobe signal to the D/A convertor IC (MAIN unit; IC15, pin 6). I/O port for the communicating singal 126 DATAH2M from the microphone (HM-162/2) to the transceiver. I/O port for the communicating singal 127 DATAMH2 from the transceiver to the micro- phone (HM-162/2). 4 - 7