at89s53-33pc ATMEL Corporation, at89s53-33pc Datasheet - Page 2

• Manufacturer Part Number: at89s53-33pc
• Description: At89s53, In-system Programmable Microcontroller With 12k Bytes Flash. For New Designs Use At89s8253.
• Manufacturer: ATMEL Corporation

Pin Configurations
Pin Description
VCC
Supply voltage.
GND
Ground.
Port 0
Port 0 is an 8-bit open drain bidirectional I/O port. As an
output port, each pin can sink eight TTL inputs. When 1s
are written to port 0 pins, the pins can be used as high-
impedance inputs.
2
(MOSI) P1.5
(MISO) P1.6
(INT0) P3.2
(INT1) P3.3
(SCK) P1.7
(RXD) P3.0
(TXD) P3.1
(T0) P3.4
(T1) P3.5
AT89S53
RST
NC
(T2 EX) P1.1
(MOSI) P1.5
(MISO) P1.6
(INT0) P3.2
(INT1) P3.3
(SCK) P1.7
(RXD) P3.0
(TXD) P3.1
(WR) P3.6
(RD) P3.7
(SS) P1.4
(T2) P1.0
(T0) P3.4
(T1) P3.5
1
2
3
4
5
6
7
8
9
10
11
XTAL2
XTAL1
GND
P1.2
P1.3
RST
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
PDIP
TQFP
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
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)
Port 0 can also be configured to be the multiplexed low-
order address/data bus during accesses to external
program and data memory. In this mode, P0 has internal
pullups.
Port 0 also receives the code bytes during Flash program-
m i n g a n d o ut p u t s th e c o d e b y t e s d u ri n g p r o g r a m
verification. External pullups are required during program
verification.
Port 1
Port 1 is an 8-bit bidirectional I/O port with internal pullups.
The Port 1 output buffers can sink/source four TTL inputs.
When 1s are written to Port 1 pins, they are pulled high by
the internal pullups and can be used as inputs. As inputs,
Port 1 pins that are externally being pulled low will source
current (I
IL
) because of the internal pullups.
(MOSI) P1.5
(MISO) P1.6
(INT0) P3.2
(INT1) P3.3
(SCK) P1.7
(RXD) P3.0
(TXD) P3.1
(T0) P3.4
(T1) P3.5
RST
NC
7
8
9
10
11
12
13
14
15
16
17
PLCC
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)
0787E–MICRO–3/06