Casio AT-1 User Manual

— 10 —
The following table shows the pin functions of the key touch LSI.
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
C222(H)
C103(H)
AG
AG
1K
AG
To main volume
-
+
IC105
M5218APR
10V22µ
C333(H)
Q107/108
2SC1740
18K
AVEE
50V1µ
From the DAC
Pin No. Terminal In/Out Function
1 REQB Out Interrupt request. Not used.
FI8 ~ FI10
SI8 ~ SI10
4 VCC In +5 V source
5 CRDB In Read enable signal
6 CWRB In Write enable signal
7 CCBB In Chip select signal
8, 9, 11 T, STBY, W In Not used. Connected to +5 V.
10 RESB In Reset signal
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 (0 V) 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 (0 V) source
29 ~ 31 CR0 ~ CR2 In Address bus
32 VCC In +5 V source
33 ~ 39, 41 ~ 43 FI0 ~ FI7,
53 ~ 55, 57 ~ 59 SI0 ~ SI7
40 VCC In +5 V source
44 ~ 47, 49 ~ 52 KC0 ~ KC7 Out Key scan signal
48, 56 GND In Ground (0 V) source
64 VCC In +5 V source
In Key input signal. Connected to + 5 V.2, 3, 60 ~ 63
In Key input signal

Casio AT-1 Specifications

General

Brand	Casio
Model	AT-1
Category	Electronic Keyboard
Language	English