Icom IC-F3GT, IC-F3GS service manual Ptt

4-5 PORT ALLOCATIONS

4-5-1 CPU (IC8)

Pin	Port	Description
number	name
1	VIN	Input port for battely voltage detection.
9	RESET	Input port for RESET signal.
11	CSIFT	Outputs reference	oscillator	for	the
		CPU control signal.
12	SCK	Outputs clock signal to the		PLL	IC
		(IC1), EEPROM (IC7), etc.
		• Outputs strobe	signals	to	the
15	DAST	expander IC (IC10, pin 6).
		• Input port for the initial version sig-
		nal.
16	CLIN	Input port for the cloning signal.
17	CLOUT	Outputs the cloning signal.
18	PLST	Outputs strobe signals to the PLL IC
		(IC1, pin 3).
19	NOIS	Input for for noise signals (pulse type).
21	BUSY	Outputs BUSY detection.
		Low: The channel is busy.
26, 36,	OPV1–3	Input port for the optional unit detec-
37		tion signal from J5.
		Outputs Wide/Narrow mode		control
38	NWC	signal.
		High: Wide mode is selected.
44–47	KR3–	Output ports for key matrix.
	KR0	Low: When the key is pushed.
		• Outputs RX mute control signal.
49	RMUT	• Input port for the RX mute signal
		from optional units.
		• Output TX mute control signal.
50	MMUT	• Input port for the TX mute signal
		from optional units.
		Outputs low-pass filter cut-off frequen-
51	DUSE	cy control signal when DTCS is acti-
		vated.
52	S5C	Outputs S5 regulator control signal.
		Low: While power is ON.
53	R5C	Outputs R5 regulator control signal.
		Low: While receiving.
54	T5C	Outputs T5 regulator control signal.
		Low: While transmitting.
55	TXC	Outputs APC circuit control signal.
		High: While transmitting.
		Outputs control signal for the regulator
56	AFON	circuit of AF power amplifier.
		High: When squelch is open, etc.
57	LIGT	Outputs LCD backlight control signal.
		High: Lights ON.
58	ESCK	Outputs EEPROM (IC7, pin 6) clock
		signal.
59	ESDA	I/O port for data signals from/to EEP-
		ROM (IC7, pin 5)

CPU (IC8)–continued

Pin	Port	Description
number	name
		Input port for unlock signal.
63	UNLK	High: PLL is unlocked.
		Low: PLL is locked.
		Output port for:
90	MTONE	Beep audio while receiving.
		2/5-tone signals while transmitting.
91	DTMF	Outputs DTMF tone signal while trans-
		mitting.
94	CTCIN	CTCSS/DTCS signals input port for
		decording.
95	PTT	Input port for the [PTT] switch.
		High: While [PTT] switch is pushed.
96	BDET	Input port for the battery’s type detec-
		tion.
97	REMO	Input port for the remote-control signal
		from external MIC (HM-75).
98	SD	Input port for the RSSI detection.
99	LVIN	Input port for the PLL lock voltage.
100	TEMP	Input port for the transceiver’s internal
		temperature detection.

4-5-2 OUTPUT EXPANDER IC (IC10)

Pin	Port	Description
number	name
2, 3,	T1–T4	Output tunable bandpass filter control
10, 11		signals.
6	DAST	Input port for strobe signal from the
		CPU (IC8, pin 15).
7	SCK	Input port for clock signal from the
		CPU (IC8, pin 12).

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