Casio GZ-500 User Manual

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AVDD
1K
1K
1K
C222(H)
C103(H)
AG
AG
1K
AG
To main volume
-
+
IC105
M5218APR
10V22
µ
C333(H)
Q107/108
2SC1740
18K
50V1
µ
From the DAC
1K
AG
AVDD
The following table shows the pin functions of LSI107.
Pin No.
Terminal
In/Out
Function
1
REQB
Out
 Not used
2, 3, 60 ~ 63
FI8 ~ FI10, 
SI8 ~ SI10
In
 Not used. Connected to + 5V.
4
VCC
In
 +5V source
5
CRDB
In
 Read enable signal input
6
CWRB
In
 Write enable signal input
7
CCBB
In
 Chip select signal input
8, 9, 11
T, STBY, W
In
 Not used. Connected to +5V.
10
RESB
In
 Reset signal input
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 ~ 59
FI0 ~ FI7,
SI0 ~ SI7
In
 Key input signal input
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.