Sony CDX-GT550, CDX-GT50W, CDX-GT500EE Buin, Nco, Sircs, Iluin, Reset NCO, Buson, CD on

CDX-GT50W/GT500/GT500EE/GT550

Pin No.	Pin Name					I/O	Pin Description
52		KEYACK				I	Key acknowledgment detect signal input
53	TU ATTIN					I	Tuner mute zero cross detect signal input (AEP, UK model only)
54					BUIN	I	Back-up power supply detect signal input
55					NCO	O	Not used. (Open)
56					DAVN	I	RDS data block synchronized detect signal input (AEP, UK model only)
57					NCO	O	Not used. (Open)
58					UNISI	I	SONY bus data signal input
59					UNISO	O	SONY bus data signal output
60			UNISCK			O	SONY bus clock signal output
61					NCO	O	Not used. (Open)
62					NCO	O	Not used. (Open)
63	DOOR IND					O	CD IN LED control signal output	H: On
64					SIRCS	I	Remote control signal input
65					NCO	O	Not used. (Open)
66	FSW OUT					O	D/D converter oscillater frequency shift control signal output
							L: 300 kHz, H: 400 kHz
67	DISP FLASHW					I	Display IC flash ROM write signal input
68	FLASH W					I	Memory mode select signal input	L: Write mode
69					NCO	O	Not used. (Open)
70	DOOR SW					I	Panel open/ close detect signal input H: Panel open
71				RC IN1		I	Rotary commander shift key signal input
72						I	Accessory power supply detect signal input
				ACC IN
73						I	Test mode detect signal input
			TESTIN
74			TELATT			I	Telephone attenuate detect signal input
75					ILUIN	I	Auto dimmer illumination detect signal input H: Ill off
76						O	A/D converter power supply control signal output
		XKEYON
77						I	CPU reset signal input
					RESET
78					NCO	O	Not used. (Open)
79					XIN	I	Sub-clock input (32.768 kHz)
80					XOUT	O	Sub-clock output (32.768 kHz)
81					VSS1	—	Ground pin
82	OSC OUT					O	Main-clock output (18.432 MHz)
83				OSC IN		I	Main-clock input (18.432 MHz)
84					VCC3	—	Power supply pin (+3.3 V)
85					SEL2	O	Not used in this set. (Open)
86					SEL5	O	Not used in this set. (Open)
87						O	Bus on signal output
				BUSON
88					SEL3	O	Not used in this set. (Open)
89	EJECT OK					O	Eject OK signal output
90 to 92					NCO	O	Not used. (Open)
93			Z-MUTE			I	CD zero cross mute detect signal input
94, 95					NCO	O	Not used. (Open)
96	CYRIL SEL					I	Cyril select signal input L: Cyril off, H: Cyril on
97					SEL4	O	Not used in this set. (Open)
98					CD ON	I	CD mechanism power control request signal input
99		CDM ON				I	CD mechanism deck power control request signal input
100					NCO	O	Not used. (Open)

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