1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
Vcc
P0.0(AD0)
P0.1(AD1)
P0.2(AD2)
P0.3(AD3)
P0.4(AD4)
P0.5(AD5)
P0.6(AD6)
P0.7(AD7)
P2.0(A8)
P2.1(A9)
P2.
2
(A10)
P2.
3
(A11)
P2.
4
(A12)
P2.
5
(A13)
P2.
6
(A14)
P2.
7
(A15)
PSEN
ALE/PRO
G
EA/VPP
(T2)P1.0
(T2EX)P1.1
P1.2
P1.3
P1.4
P1.5
P1.6
P1.7
RST
(RXD)P3.0
(TXD)P3.1
(INT0)P3.2
(INT1)P3.3
(T1)P3.5
(T0)P3.4
(WR)P3.6
(RD)P3.
7
XTAL1
XTAL2
GND
AT89S51/W78E
052DDG
MAIN BOARD : IC5
0
1
PIN CONFIGURATION
OSC
WATCH
DOG
PORT 1
LATCH
LATCH
LATCH
LATCH
PORT 0
PORT 2
PORT 0 DRIVERS
PORT 1 DRIVERS
PORT 2 DRIVERS
PORT 3 DRIVERS
QUICK
FLASH
RAM
RAM ADDR.
REGISTER
REGISTER
B
ACC
STACK
PIONTER
PROGRAM
ADDRESS
REGISTER
BUFFER
PC
INCREMENTER
PROGRAM
COUNTER
DUAL DPTR
INTERRUPT ,SERIAL PORT
AND TIMER BLOCKS
TMP2
TMP1
ALU
PSW
TIMING AND
CONTROL
INSTRUCTION
REGISTER
P1.0 ------ P1.7
P3.0 ------ P3.7
P2.0 ------ P2.7
P1.0 ------ P1.7
PORT 3
PORT
ISP
PROGRAM
LOGIC