reset
reset
DB0
DB1
DB2
DB3
DB4
DB5
DB6
DB7
ADDR0
ADDR1
ADDR2
KEYIN1
KEYIN2
KEYIN3
LED0
LED1
LED2
LED3
LED4
LED5
LED6
LED7
KEYIN1
KEYIN2
KEYIN3
DB0
DB1
DB2
DB3
DB4
DB5
DB6
D0
D1
D2
D3
D4
D5
D6
D7
DB7
ADDR0
ADDR1
D0
D1
D2
D3
D4
D5
D6
D7
DL0
DL1
DL2
DL3
DL4
DL5
DL6
DL7
ADDR2
LED0
LED1
LED2
LED3
LED4
LED5
LED6
LED7
DL0
DL1
DL2
DL3
DL4
DL5
DL6
DL7
XTAL2
18
XTAL1
19
ALE
30
EA
31
PSEN
29
RST
9
P0.0/AD0
39
P0.1/AD1
38
P0.2/AD2
37
P0.3/AD3
36
P0.4/AD4
35
P0.5/AD5
34
P0.6/AD6
33
P0.7/AD7
32
P1.0
1
P1.1
2
P1.2
3
P1.3
4
P1.4
5
P1.5
6
P1.6
7
P1.7
8
P3.0/RXD
10
P3.1/TXD
11
P3.2/INT0
12
P3.3/INT1
13
P3.4/T0
14
P3.7/RD
17
P3.6/WR
16
P3.5/T1
15
P2.7/A15
28
P2.0/A8
21
P2.1/A9
22
P2.2/A10
23
P2.3/A11
24
P2.4/A12
25
P2.5/A13
26
P2.6/A14
27
U2
AT89C51
A
7
QA
13
B
1
QB
12
C
2
QC
11
D
6
QD
10
BI/RBO
4
QE
9
RBI
5
QF
15
LT
3
QG
14
U3
74LS48
X1
CRYSTAL
C1
20pf
C2
20pf
BUTTON1
reset
C3
1nF
R1
18
R2
4.7K
A
1
B
2
C
3
E1
6
E2
4
E3
5
Y0
15
Y1
14
Y2
13
Y3
12
Y4
11
Y5
10
Y6
9
Y7
7
U1
74HC138
R11
10k
R12
10k
R13
10k
A0
2
B0
18
A1
3
B1
17
A2
4
B2
16
A3
5
B3
15
A4
6
B4
14
A5
7
B5
13
A6
8
B6
12
A7
9
B7
11
CE
19
AB/BA
1
U4
74HC245
R14
4.7k
R15
4.7k
R16
4.7k
R17
4.7k
R18
4.7k
R19
4.7k
R20
4.7k
R21
4.7k
R22
4.7k
R23
4.7k
R24
4.7k
R25
330
R26
330
R27
330
R28
330
R29
330
R30
330
R31
330
R32
330
1 2
U5:A
74LS04
3 4
U5:B
74LS04
5 6
U5:C
74LS04
13 12
U5:D
74LS04
11 10
U5:E
74LS04
9 8
U5:F
74LS04
1 2
U6:A
74LS04
3 4
U6:B
74LS04