Power Supply Circuits; Cpu Port Allocations - Icom IC-M422 Service Manual

4-6 POWER SUPPLY CIRCUITS

Line
HV The voltage from the connected DC power supply.
Common 5V converted from the HV line at the L5V regulator
(LOGIC BOARD; IC3).
L5V
The converted voltage is applied to the CPU (LOGIC
BOARD; IC1)
Same voltage as the HV line whitch is passed through the
VCC
power control circuit (Q61, Q62).
Common 5V converted from the VCC line at the +5 regulator
S5V
circuit (IC10).
Transmit 5V controlled by the T5 control circuit (Q52, Q57)
T5
using the "SEND" signal from CPU (LOGIC BOARD; IC1, pin 52).
Receive 8 V converted from the VCC line at the R8 regulator
R8 (Q55, Q56).
The converted voltage is applied to the receiver circuits.
Receive 5V controlled by the R5 control circuit (Q53, Q54)
using the "RCV" signal from CPU (LOGIC BOARD; IC1,
R5
pin 53).
The controlled voltage is applied to the receiver circuits.

4-7 CPU PORT ALLOCATIONS

Pin
Port name
NO.
Input port for keys on HM-150B/SW.
Approx. 2.02 V: [Y] key is pushed.
2 KEYM
Approx. 3.00 V: [Z] key is pushed.
Approx. 3.84 V: [H/L] key is pushed.
3 TXDET Input port for transmit detected voltage.
4 LBAT Input port for low battery detecting.
Input port for "NOISE" signal from the squelch
5 SQL
amplifi er (IC11, pin 4).
Input port for squelch adjustment pot (SQL
6 SQLV
BOARD; R1).
Input port for weather alert signal from the
7 WXDEC
LPF (Q38).
8 PDATA Outputs data signal to the PLL IC (IC1, pin 5).
9 PCK Outputs clock signal to the PLL IC (IC1, pin 4).
10 PSTB Outputs strobe signal to the PLL IC (IC1, pin3).
Outputs volume control signal to the volume
12 EVDATA
ccontroller (IC13, pin 5) for PA circuit.
Outputs clock signal to the volume ccontroller
13 EVCK
(IC13, pin 4) for PA circuit.
Input port for the DSC decode signal from the
14 DSDEC
DSC decoder (IC15, pin 7).
28, CONT1, Output LCD contrast adjust signal to the CPU
29 CONT0 (IC1, pin 134).
Outputs serial data signal to the connected
32 COMTXD
HM-157 (Optional product).
Input port for the serial data signal from the
33 COMRXD
connected HM-157 (Optional product).
Outputs clock signal to the EEPROM (LOGIC
34 ECK
BOARD; IC4, pin 6).
I/O port for the EEPROM (LOGIC BOARD;
35 EDATA
IC4, pin 5) control data.
37 NMTXD Outputs NMEA command signal.
Description
Description
Pin
Port name
NO.
38 NMRXD Input port for the NMEA signal.
Input port for power switch (VR BOARD; R1).
48 PWR
Outputs control signal to the AF (Public Ad-
49 PAMUTE dress) mute circuit (Q65).
Outputs power control signal to the power
50 PWRON control circuit (Q61, Q62).
Outputs transmit mute signal to the APC circuit
51 TMUTE (IC12, pin 3).
Outputs control signal to the R5 control circuit
53 RCV (Q53, Q54).
Outputs TX power control signal to the TX
power control circuit (Q17, D11).
54 H/L
Outputs attenuator control signal to the
55 ATT attenuator (D22).
Input port for the [PTT] switch (HM-150B/SW; S1).
57 PTT
Input port for the "UNLK" signal from the PLL
60 UNLK IC (IC1, pin7).
Input port for the [DISTRESS] key (LOGIC
61 DTRS BOARD; S9).
Outputs AF (Public Address) mute signal to
62 RMUTEP the AF mute circuit (IC4, pin12).
Outputs AF mute signal to the AF mute circuit
(IC4, pin 5) for the connected HM-157 (Op-
63 RMUTES
tional product).
Outputs AF (internal speaker) mute signal to the
AF mute circuit (IC4, pin 6).
64 RMUTEM
Outputs microphone (Public Address) mute
65 MMUTEP signal to the AF mute circuit (IC5, pin 6).
Outputs microphone mute signal to the AF
mute circuit (IC5, pin 5) for the connected
66 MMUTES
HM-157 (Optional product).
Outputs microphone (HM-150B/SW) mute sig-
67 MMUTEM nal to the AF mute circuit (IC5, pin 13).
Outputs AF/MIC control signal to the AF mute
68 PTTS circuit (IC6, pin 5).
Outputs AF/MIC control signal to the AF mute
69 PTTM
circuit (IC5, pin 12).
Input por t for the [LO/DX] key (LOGIC
70 LO/DX BOARD; S8).
4 - 4
Description
Low: When [VOL] is pushed.
High: During mute.
High: While the transceiver is switched ON.
High: During mute.
High: While receiving.
High: 25 W
Low: 1 W
High: Attenuator ON.
Low: [PTT] key is pushed.
High: PLL circuit is unlocked.
Low: [DISTRESS] key is pushed.
Low: During mute.
Low: During mute.
Low: During mute.
Low: During mute.
Low: During mute.
Low: During mute.
High: PTT switch (HM-157) is pushed
Low: [LO/DX] key is pushed.