Sony CDX-828 - Compact Disc Changer System, Service Manual

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MAIN BOARD IC501 CXP83413-049Q (CD TEXT DECODER)
Pin No. Pin Name I/O Function
1, 2 NC O Not used (open)
3 NC I Not used (fixed at “L”)
4 REQ O
Request signal output to the system controller (IC201) “L” active
5 CCLK I
Serial data transfer clock signal input from the system controller (IC201)
6 CSI I
Serial data input from the system controller (IC201)
7 CSO O
Serial data output to the system controller (IC201)
8 SCLK O
Clock signal output for subcode data reading to the CXD2530Q (IC101)
9 SSI I
Subcode data input from the CXD2530Q (IC101)
10 NC O Not used (open)
11 to 18 ADD0 to ADD7 O
Address signal output to the S-RAM (IC502)
19 NC I Not used (fixed at “L”)
20 to 27 DATA0 to DATA7 I/O
Two-way data bus with the S-RAM (IC502)
28 RST I
System reset signal input from the system controller (IC201), SONY bus interface (IC302) and
reset signal generator (IC304) “L”: reset
For several hundreds msec. after the power supply rises, “L” is input, then it changes to “H”
29 EXTAL I
System clock input terminal (10 MHz)
30 XTAL O
System clock output terminal (10 MHz)
31 VSS —
Ground terminal
32 to 55 NC O
Not used (open)
56 BUSY O
Busy signal output to the system controller (IC201) “L”: busy status
57 to 61 NC O
Not used (open)
62 CE O
Chip enable signal output to the S-RAM (IC502) “L” active
63 WE O
Data write enable signal output to the S-RAM (IC502) “L” active
64 to 69 ADD8 to ADD13 O
Address signal output to the S-RAM (IC502)
70 VDD —
Power supply terminal (+5V)
71, 72 NC O
Not used (open)
73 NC I
Not used (fixed at “H”)
74 ADD14 O
Address signal output to the S-RAM (IC502)
75 NC O
Not used (open)
76 SCOR I
Subcode sync (S0+S1) detection signal input from the CXD2530Q (IC101)
77 WFCK I
Write frame clock (7.35 kHz) signal input from the CXD2530Q (IC101)
78 BUCK I
Backup power supply detection signal input terminal (used also to reset standby)
79, 80 NC I
Not used (fixed at “L”)