Casio CTK-650, Service Manual, Page: 6 / 22

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DIGITAL SIGNAL PROCESSOR, LSI-S (HG51A115A01FD)
The LSI-S is a 16-bit DSP(Digital Signal Processor) and accessable to 16M-bit sound source ROM and to 64K-
bit RAM. The DSP can read data of 32 polyphonic note from the ROM and provides two 16-bit serial dat with
timing signals to each channel's D/A converter.
Pin No. Terminal In/Out Function
1~7 D7~D0 I/O Data bus.
11 GND7 In Ground(0V) source.
12 CK16 Out 16.384MHz clock pulse output.
13 VCC6 In +5V source
14 CK0 In Clock pulse input. Connected to terinal CK16.
16 VCC1 In +5V source.
17 GND1 In Ground(0V) source.
18,19 XTI, XTO In/Out 16.384MHz clock pulse input/output. Connected to crystal.
21 CCSB I Chip select signal input.
22~25 CA0~CA3 In Address bus.
26 CE0 In Connected to ground.(ROM interface ontrol terminal)
27 CWRB In Write enable signal.
28 CRDB In Read enebla signal.
33 RESB In Reset sna iput
34 TESB In Connected to +5V.
40~49
52~57
RD0~RD15 In Data bus for sound source ROM.
50 VCC2 In +5V source.
51 GND2 In Ground(0V) source.
59 RA22 Out Chip enable signal output for ROM.
62~73
75~82
RA0~RA19 Out Address bus for sound source ROM.
74 GND5 In Ground(0V) source.
84 VCC3 In +5V source.
85 GND3 In Ground source.
86 WOK1 Out Ward clock for DAC.
88 SOLP Out 16-bit serial data for L-channel DAC.
89 BOK Out Bit clock for DAC.
93 VCC5 In +5V source.
95,97
99~105
107,109
110,112
EA0~EA12 Out Address bus for RAM.
96 EWEB Out Write enable signal for RAM.
106 EOEB Out Read enable signal for RAM.
108 VCC7 In +5V source.
111 ECEB Out Chip eneble signal for RAM.
118 VCC4 In +5V source.
119 GND4 In Ground(0V) source.
123~130 ED0~ED7 In/Out Data bus for RAM.
131 GND6 In Connected to Ground.
132 SSI In Connected to Ground.
133 SBCK In Connected to Ground.
134 SWCK In Connected to Ground.