AT89S8252-16JA ATMEL [ATMEL Corporation], AT89S8252-16JA Datasheet - Page 2

• Manufacturer Part Number: AT89S8252-16JA
• Description: 8-Bit Microcontroller with 8K Bytes Flash
• Manufacturer: ATMEL [ATMEL Corporation]

Pin Configurations
Pin Description
VCC
GND
Port 0
Port 1
2
AT89S8252
(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
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
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)
Supply voltage.
Ground.
Port 0 is an 8-bit open drain bi-didirectional 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.
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 pull-ups.
Port 0 also receives the code bytes during Flash programming and outputs the code
bytes during program verification. External pull-ups are required during program
verification.
Port 1 is an 8-bit bi-directional I/O port with internal pull-ups. 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 pull-ups and can be used as inputs. As inputs, Port 1 pins that are exter-
nally being pulled low will source current (I
(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)
(MOSI) P1.5
(MISO) P1.6
(RXD) P3.0
(INT0) P3.2
(INT1) P3.3
(SCK) P1.7
(TXD) P3.1
(T0) P3.4
(T1) P3.5
RST
IL
NC
) because of the internal pull-ups.
1
2
3
4
5
6
7
8
9
10
11
TQFP
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)
0401F–MICRO–11/03