AT89C55WD Atmel Corporation, AT89C55WD Datasheet - Page 2

• Manufacturer Part Number: AT89C55WD
• Manufacturer: Atmel Corporation

Specifications of AT89C55WD

• Flash (kbytes): 20 Kbytes
• Max. Operating Frequency: 24 MHz
• Cpu: 8051-12C
• Max I/o Pins: 32
• Uart: 1
• Sram (kbytes): 0.25
• Operating Voltage (vcc): 4.0 to 6.0
• Timers: 3
• Watchdog: Yes

2. Pin Configurations
2.1
2.2
2.3
2
44A – 44-lead TQFP
44J – 44-lead PLCC
40P6 – 40-lead PDIP
AT89C55WD
(INT0) P3.2
(INT1) P3.3
(RXD) P3.0
(TXD) P3.1
(T0) P3.4
(T1) P3.5
(RXD) P3.0
(INT0) P3.2
(INT1) P3.3
(TXD) P3.1
(T0) P3.4
(T1) P3.5
P1.5
P1.6
P1.7
RST
NC
P1.5
P1.6
P1.7
RST
NC
(T2EX) P1.1
(RXD) P3.0
(INT0) P3.2
(INT1) P3.3
(TXD) P3.1
(WR) P3.6
(RD) P3.7
(T2) P1.0
(T0) P3.4
(T1) P3.5
7
8
9
10
11
12
13
14
15
16
17
1
2
3
4
5
6
7
8
9
10
11
XTAL2
XTAL1
GND
P1.2
P1.3
P1.4
P1.5
P1.6
P1.7
RST
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
40
39
38
37
36
35
34
33
32
31
30
29
28
27
26
25
24
23
22
21
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)
EA/VPP
ALE/PROG
PSEN
P2.7 (A15)
P2.6 (A14)
P2.5 (A13)
P2.4 (A12)
P2.3 (A11)
P2.2 (A10)
P2.1 (A9)
P2.0 (A8)
33
32
31
30
29
28
27
26
25
24
23
39
38
37
36
35
34
33
32
31
30
29
P0.4 (AD4)
P0.5 (AD5)
P0.6 (AD6)
P0.7 (AD7)
EA/VPP
NC
ALE/PROG
PSEN
P2.7 (A15)
P2.6 (A14)
P2.5 (A13)
P0.4 (AD4)
P0.5 (AD5)
P0.6 (AD6)
P0.7 (AD7)
EA/VPP
NC
ALE/PROG
PSEN
P2.7 (A15)
P2.6 (A14)
P2.5 (A13)
1921D–MICRO–6/08