Icom IC F121S, IC F110S, IC F111S service manual Cpu

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Pin	Port	Description
number	name
		Outputs control signal for the power
41	PWON	switching circuit (MAIN unit; Q24,
		Q23).
42	NWC	Outputs IF bandwidth control signal.
		Low : While IF bandwidth is narrow.
		Outputs control signal for the AF mute
43	AFON	circuit (MAIN unit; Q35, Q36, D29).
		High : While AF amplifier (MAIN unit;
		IC8) is activated.
44–46	OPT3–	I/O ports for the optional board control
	OPT1	signals.
47	BUSY	Outputs BUSY detection signal for the
		optional board via MAIN unit, J1.
48	SI	Input port for the clock signal from the
		optional board via MAIN unit, J1.
49	CLI	Input port for the cloning signal.
50	CLO	Output port for the cloning signal.
51	POSW	Input for the POWER switch.
		Input port for the remote power control
52	IGSW	signal from external connector (MAIN
		unit; J6).
53	NOIS	Input port for the “NOIS” signal which
		ºis used noise squelch operation from
		the FM IF IC (MAIN unit; IC1).
		Input port for the interruption signal
54	CIRQ	from the optional board via MAIN unit,
		J1.
55	CCS	Outputs the chip select signal for the
		optional board via MAIN unit, J1.
56	PTT	Input port for the PTT switch from
		microphone.
		Input port for the PTT switch from the
57	EPTT	external connector (MAIN unit; J6).
		Low : External PTT switch is ON.
		Input port for the microphone hanger
58	HANG	detection signal.
		Low ; Microphone on hook.
		Input port for the AF volume control
59	AFVI	(FRONT unit; R14).
		High : [VOL] is maximum clockwise.
60	CDEC	Input port for CTCSS/DTCS decoding
		signals.
61	SDEC	Input port for the single tone decoding
		signals.
62	OPV1V2	Input port for the optional board detec-
		tion signal.
63	RSSI	Input port for the detection signal of the
		received signal strength.
64	LVIN	Input port for the PLL lock voltage.

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