4

4247DS–SCR–03/07

AT83C21GC

Pin Description

Figure 2. 24-pin SSOP Pinout

Figure 3. 32-pin QFN Pinout

P1.1/CC8

P1.4/CCLK

P1.0/CIO

RST

P1.5/CRST

1

P1.3/CC4

P1.2/CPRES

XTAL1

P3.3/INT1/OE

P3.2/INT0

P3.4/T0

P3.5/CIO1/T1

LI

C

CVSS

V

CC

E

VSS

P3.0/RxD

P3.1/TxD

2

3

4

5

6

7

8

9

10

11

12

24

23

22

21

20

19

18

17

16

15

14

13

P3.6/CCLK1/LED0

XTAL2

P3.7/CRST1/LED1

D

V

CC

SSOP24

QFN32

Vss

P1.1/CC8

P1.0/CIO

P1.2/CPRES

CVcc

P1.4/CCLK

P3.5/CIO1/T1

P1.3/CC4

P1.5/CRST

P3.4/T0

P3.0/RxD

28 27 26

1

2

3

4

5

6

7

24

23

22

21

20

19

18

12

11

10

9

13 14 15

RST

8

16

17

Vss

P3.1/TxD

25

29

30

31

32

P3.2/INT0

P3.3/INT1/OE

Table 1. Port Signal Description

Port

Signal

Name

Internal

Power

Supply

ESD

Type

Description

P1.0

CIO

4 kV

I/O

Smart Card Interface Function

Card I/O – Pull-up medium is lower than 20KΩ

P1.1

CC8

4 kV

I/O

Smart Card Interface Function

Card contact 8 – Pull-up medium must be less than 20KΩ

P1.2

CPRES

4 kV

I

Smart Card Interface Function

Card presence