Icom IC-F4TR Service Manual page 10

4-5 PORT ALLOCATIONS
CPU (IC17)
Pin Port
number name
1 RES Input port for the reset signal.
Input port for writing control signal.
5 MD1
Low : Writing to CPU (IC17)
10 CSHIFT Outputs CPU clock shift signal.
11 MODEL Input port for model detect signal.
Input port for the cloning data from the
13 RXD
buffer (D27).
Output port for the cloning data to the
14 TXD
buffer (Q31).
Outputs data signal for the DTMF
16 DTMFSO
encoder (IC15).
Outputs clock signal for the DTMF
18 DTMFCK
encoder (IC15).
Outputs strobe signals to the expander
19 DAST
IC (IC10).
Input port for the DTMF clock signal
20 DTACK
from the DTMF decoder (IC24).
Input port for the DTMF decoding sig-
21 DTSD
nal from the DTMF decoder (IC24).
26 SN RX I/O port for the optional unit.
Outputs bandwidth control signal for
29 BWC
the data filter (IC12).
Input port for noise signals (pulse-
32 NOISE
type) for noise squelch operation.
Outputs mic. audio mute control signal
to the audio switch (IC25).
33 MMUTE
High : While DTMF signals are being
38 BATIN Input port for battery voltage detection.
Input port for receiving signal strength
39 RSSI
level detection.
Input port for the internal temperature
40 TEMPS
detection.
Input port for the current detection sig-
41 ISENS nal from the current sensor circuit (Q9,
Q28, R161).
42 LVIN Input port for PLL lock voltage.
Input port for the subaudible tone
43 TDET
decoding.
44 SAUD Output port for the subaudible tone
Outputs serial signal for the LCD dri-
49 MSO
ver, EEPROM and etc.
Input port for serial signal from the
50 MSI
LCD driver, EEPROM and etc.
Outputs clock signal for the LCD dri-
51 MSCK
ver, EEPROM and etc.
Outputs R5 regulator control signal.
52 R5C
Low: While receiving
Description
transmitted, etc.
Pin Port
number name
53 BEEP
54 T5C
55 TMUT
57 VCOSW
60 ULOCK
62 PLLST
63 PLLSO
64 PLLSK
65 W/N
CLR/
78
CODE
79 OPTB
81 BKLED
84 RMUTE
85 AFON
90 PTTIN
91 TXLED
93 S5C
94 FSW
95 SN TR
96 EEPCS
97 XTXD
98 XRXD
99 DTSTD
4 - 4
Description
Outputs beep audio signals.
Outputs T5 regulator control signal.
Low: While transmitting
Outputs transmit mute signal.
High : During unlock or while muted
Outputs VCO switching signal.
High : While transmitting
Input port for the PLL unlock signal.
High : During unlock
Outputs strobe signals for the PLL IC
(IC1).
Outputs data signal for the PLL IC
(IC1).
Outputs clock signal for the PLL IC
(IC1).
Outputs N/W switch control signal.
High : While narrow is selected
I/O port for the optional unit.
I/O port for the optional unit.
Outputs LCD backlight control signal.
High : LCD backlight is ON
Outputs the analog switch (IC4) con-
trol signal (incl. beep).
Low : While squelched, etc.
Outputs the control signal for the AF
amplifier regulator circuit.
High: While AF amp. is activated.
Input port for the PTT control signal
from the PTT control switch (Q17).
Outputs TX LED control signal.
Outputs S5 regulator control signal.
Outputs high-pass filter's characteris-
tics select signal.
High : During CTCSS operation
I/O port for the optional unit.
Outputs chip select signal for EEP-
ROM.
Output port for the programming data
to a flash writter.
Input port for the programming data
from a flash writter.
Input port for data signal from DTMF
decoder (IC24).