Table Of 1C Pin Functions - Yamaha DX21 Service Manual

DX21
■ TABLE OF 1C PIN FUNCTIONS
YM2164 OPP
1
Pin Name I/O
____________----—
Function
Remarks
Vss - GND
' ' .I.
IRQ 1RQ output port
mm
7c 1
"L" reset input (Active Low)
Ao
1
Internal register selection signal input
WT 1 Data write request input from CPU
RD
1 Data read request input from CPU
•
CS 1
Chip selection input
CTl 0 Filter characteristics switch or control signal output for voice
synthesizing
CJ2
0
"
D„
I/O 3-state data bus I/O port
Vss - GND
0,
I/O
Bgfli
t
r 3-state data I/O port
■|fl||B
d7
I/O
J
SH2 0
T
rnimmi SHI
0
J
Signal output for L/R separation
21
So
0
Sound generation serial data (L/R)
22 Vcc - Power +5V
01 0 Clock output for DAC synchronization
0M 1 CPU master clock input for synchronization with CPU
YM3012
DAC
Pin No. Pin Name I/O Remarks
1 Vcc - +5V
2 CLOCK 1
Timing clock input for synchronization with OPP
3 GND
-
Digital GND
IIIIII
DATA 1 Voice serial data input
SAM 1
1 Data input for sampling (for L/R separation)
6 SAM 2 1
( " )
ICL 1 Initial clear input
§$0$%
GND
-
Analog GND
CH 1 0
CHI (L ch) analog signal output
WMMii$.
CH 2 0
CH2 (R ch)
COM
1
L/R Separation input
To BUF 0
DAC Analog output
pll j
Mid. Point 1
Reference voltage input of analog signal
W&MA
BC 0
Bias compensation
15 RB 0 1/2 Vcc bias regulator output
16
GND
-
6