Port Allocations - Icom IC-T2H Service Manual

4-5 PORT ALLOCATIONS

CPU (IC8)
Pin Port
number name
Input port for CTCSS signal for decod-
1 CIN
ing.
9 RESET Input port for the reset signal.
Output reference oscillator for the
11 CSIFT
CPU control signal.
Output clock signal to the PLL (IC1)
12 SCK
and EEPROM (IC7) ICs, etc.
Input port for the data signals from
13 SI
EEPROM (IC7), etc.
Output data signal to the PLL (IC1)
14 SO
and EEPROM (IC7) ICs, etc.
Input port for PLL unlock signal from
15 UNLK
the PLL IC (IC1).
High: During unlock
16 CLIN Input port for the cloning signal.
17 CLOUT Output port for the cloning signal.
Outputs strobe signals to the PLL IC
18 PLST
(IC1).
Input port for noise signals (pulse
19 NOIS
type) from the FM IF IC (IC2, pin 13).
Outputs LCD contrast control signal.
26 CONT
High: When normal level is selected.
36–41 KS0–KS5 Output ports for key matrix.
Outputs the analog switch (IC4) con-
trol signal.
42 MMUT
Low : While DTMF or ANI signals
Outputs the analog switch (IC4) con-
43 RMUT trol signal.
Low : While muted.
44–47 KR0–KR5
Input ports for key matrix.
Outputs R5 regulator control signal.
48 R5C
Low : While receiving
Output S5 regulator control signal.
49 S5C
Low : While power is ON.
Outputs transmit output power select
50 TXC (HIGH or LOW) signal.
Low : HIGH power is selected.
Input ports for the [PTT] switch.
51 T5C
High: While [PTT] is pushed
Outputs LCD backlight control signal.
52 LIGHT
High: When backlighting is ON
Outputs the regulator circuit control
signal for the AF amplifier.
53 AFON
High: While AF amplifier is activat-
Description
are output.
ed.
Pin Port
number name
54–60 T4/PWR
90 BEEP
91 DTMF
94 PTT
96 TEMP
98 SD
100 VIN
4 - 4
Description
Output ports for:
• tunable bandpass filter control
signal while receiving.
• reference signal for the APC circuit
while transmitting.
Outputs beep audio signals.
Outputs DTMF signals while pushing
the keypad during transmit.
Input port for the [PTT] switch.
Input port for internal temperature
detection.
Input port for the S-meter signal from
the FM IF IC (IC2, pin 12).
Input port for overvoltage detection
from the connected power supply or
battery pack.