NAD T 743 Service Manual page 47

T89C51RD2
KEYBOARD: U201
XTAL1
XTAL2
ALE/ PROG
PSEN
EA
(3)
RD
(3)
WR
AT89C51RB2
KEYBOARD: U202
XTAL1
XTAL2
ALE/ PROG
PSEN
EA
(2)
RD
(2)
WR
74HC4051
KEYBOARD: U208
S-VIDEO BOARD: U4102, U4103
COMPOSITE VIDEO: U4201
74HC4051
4
1
CHANNELS
IN/OUT
6
2
COM OUT/IN
3
7
CHANNELS 4
IN/OUT
5
5
INH
6
V
7
EE
GND
8
(3) (3)
RAM
EUART
256x8
C51
CORE
IB-bus
CPU
Timer 0 INT
Timer 1 Ctrl
(3) (3) (3) (3)
(2) (2)
EUART
RAM
+
256 x 8
BRG
C51
CORE
IB-bus
CPU
T imer 0 INT
T imer 1 C trl
(2) (2) (2) (2)
V
16
CC
2
15
1 CHANNELS
14
IN/OUT
0
13
3
12
A
11
B
10
C
9
Flash
XRAM
EEPROM
64Kx8
1Kx8
2Kx8
Parallel I/O Ports & Ext. Bus
Port 4
Port 0 Port 1 Port 2 Port 3
(2)
B oot
F lash
XRAM
ROM
32K x 8 or
1K x 8
2K x 8
16K x 8
P arallel I/ O P orts & E xt . B us
P ort 0P ort 1 P ort 2 P ort 3
BA7660FS
COMPONENT VIDEO BOARD: U4301
MUTE
1
INA
2
GND
3
INB
4
GND
5
N.C.
6
INC
7
GND
8
47
(1) (1) (1)
(1)
PCA
Timer2
Watch
Dog
Port 5
(2)
(1) (1) (1) (1)
PCA
T imer 2
W atch K ey
SPI
D og B oard
(1) (1) (1) (1)
6dB 75W
6dB 75W
6dB 75W
16
V
CC
OUTA1
15
OUTA2
14
OUTB1
13
OUTB2
12
N.C.
11
OUTC1
10
OUTC2
9