— 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
Summary of Contents for CTK-750
Page 1: ...with price CTK 750 ELECTRONIC KEYBOARD R CTK 750...
Page 16: ...14 MAJOR WAVEFORMS...
Page 17: ...15...
Page 20: ...18 Console PCB M5712 CN1M...
Page 21: ...19 Keyboard PCBs M615T KY1M KY2M...
Page 22: ...20 EXPLODED VIEW...
Page 30: ...MA0300941A...
