AT89S8252-24QC ATMEL [ATMEL Corporation], AT89S8252-24QC Datasheet - Page 2

• Manufacturer Part Number: AT89S8252-24QC
• Description: 8-bit Microcontroller with 8K Bytes Flash
• Manufacturer: ATMEL [ATMEL Corporation]

Pin Configurations
Pin Description
VCC
Supply voltage.
GND
Ground.
Port 0
Port 0 is an 8-bit open drain bbi-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
2
(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
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
1
2
3
4
5
6
7
8
9
10
11
(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
PQFP/TQFP
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
AT89S8252
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)
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)
program and data memory. In this mode, P0 has internal
pullups.
Port 0 also receives the code bytes during Flash program-
mi ng an d ou tpu ts th e c ode by te s d ur i ng p r og r am
verification. External pullups are required during program
verification.
Port 1
Port 1 is an 8-bit bi-directional 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
(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 pullups.
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)