Icom IC-F3, Service Manual

Page: 12 / 52

4 - 4
4-5 CPU PORT ALLOCATIONS
4-5-1 CPU (IC8) CPU (IC8) — continued
Pin
number
1
11
12
13
14
15
18
19
26
36–41
(IC-F3/S)
40, 41
(IC-F4/S)
42
43
44–47
48
49
50
51
52
53
54
60–62
63
Port
name
CTCIN
CSIFT
SCK
SI
SO
UNLK
PLST
NOIS
CONT
KS0–KS5
KS4, KS5
MM
RM
KR0–KR5
R5C
S5C
TXC
T5C
LIGHT
AFON
DST
CTDA0–
CTDA2
DUSE
Description
Input port for CTCSS/DTCS signals
for decoding.
Outputs reference oscillator for the
CPU control signal.
Outputs clock signal to the PLL IC
(IC1), EEPROM (IC7) and expander
IC (IC10), etc.
Input port for the data signals from
EEPROM (IC7), etc.
Outputs data signals to the PLL IC
(IC1), EEPROM (IC7) and expander
IC (IC10), etc.
Input port for PLL unlock signal from
the PLL IC (IC1). High level signal is
applied during unlock.
Outputs strobe signals to the PLL IC
(IC1).
Input port for noise signals (pulse
type) from the FM IF IC (IC2).
Outputs LCD contrast control signal.
High: When normal level is selected
Output ports for key matrix.
Outputs mic. mute control signal.
Low: When DTMF or 2/5-tone sig-
nal is selected
Outputs RX mute control signal.
Low: When muted
Input ports for key matrix.
Outputs R5 regulator control signal.
Low: While receiving
Outputs S5 regulator control signal.
Low: While power is ON
Outputs T5 regulator control signal.
Low: While transmitting
Outputs T5 regulator control signal.
Low: While transmitting
Outputs LCD backlight control signal.
High: Lights ON
Outputs the regulator circuit for the
AF amplifier control signal.
High: While AF amp. is activated.
Outputs strobe signals to the
expander IC (IC10).
Outputs CTCSS and DTCS encode
signals (3-bit, D/A type).
Outputs filter switch control signal
for the CTCSS and DTCS (Q38).
High: DTCS is activated.
Pin
number
90
91
Port
name
MTONE
DTMF
Description
Output port for:
Beep audio while receiving.
2/5-tone signals while transmitting.
Output port for DTMF signals while
transmitting.
Pin
number
2
3
4
11–13
14
Port
name
DST
SCK
SO
T1–T3
T4
Description
Input port for strobe signals.
Input port for clock signal.
Input port for data signal.
Output tuneable bandpass filter
control voltage.
Outputs tuneable bandpass filter
control signal while receiving.
Outputs RF output power control
signals while transmitting.
4-5-2 OUTPUT EXPANDER IC (IC10)