User's Manual
— 11 —
The following table shows the pin functions of the key touch LSI.
Pin No. Terminal In/Out Function
1 REQB Out  Interrupt request. Not used.
2, 3 FI10, SI10 In  Key input signal
4 VCC In  +5V source
5 CRDB In  Read enable signal
6 CWRB In  Write enable signal
7 CCBB In  Chip select signal
8, 9 T, STBY In  Not used. Connected to +5V.
10 RESB In  Reset signal
11 W In  Not used. Connected to +5V.
12 CKI In  10 MHz clock input 
13, 14 TMD, TST In  Not used. Connected to ground.
15 CKO Out  Not used.
16 GND In  Ground (0V) source
17 XIN In  Not used. Connected to ground.
18 XOUT Out  Not used.
19 TRES In  Not used. Connected to ground.
20 ~ 23, 25 ~ 28 CD0 ~ CD7 In/Out  Data bus
24 GND In  Ground (0V) source
29 ~ 31 CR0 ~ CR2 In  Address bus
32 VCC In  +5V source
33 ~ 39, 41 ~ 43
53 ~ 55, 57 ~ 63
FI0 ~ FI9,
SI0 ~ SI9
In  Key input signal
40 VCC In  +5V source
44 ~ 47, 49 ~ 52 KC0 ~ KC7 Out  Key scan signal
48, 56 GND In  Ground (0V) source
64 VCC In  +5V source
Filter Block
Since the sound signals from the DAC are stepped waveforms, the filter block is added to smooth the
waveforms.
AVDD
1K
1K 1K
C182(H)
C152(H)
AG
AG
1K
AG
To main volume
-
+
M5218APR
10V22µ
C104(H)
2SC1740SQ
10K
AVEE
10V22µ
From the DAC










