EXAR Corporation, 48720 Kato Road, Fremont, CA 94538

• (510) 668-7000 • FAX (510) 668-7017

ST16C552

ST16C552A

PLCC Package

DUAL UART WITH 16-BYTE FIFO AND

PARALLEL PRINTER PORT

December 2003

Rev. 3.40

DESCRIPTION

The ST16C552/ST16C552A (552/552A) is a dual universal asynchronous receiver and transmitter (UART) with

an added bi-directional parallel port that is directly compatible with a CENTRONICS type printer. The parallel port

is designed such that the user can configure it as general purpose I/O interface, or for connection to other printer

devices. The 552/552A provides enhanced UART functions with 16 byte FIFO’s, a modem control interface, and

data rates up to 1.5Mbps. Onboard status registers provide the user with error indications and operational status.

The system interrupts and control may be tailored to meet user requirements. An internal loop-back capability

allows onboard diagnostics. A programmable baud rate generator is provided to select transmit and receive clock

rates from 50 bps to 1.5 Mbps. The 552/552A is available in a 68 pin PLCC package. The 552/552A is compatible

with the 16C450 and 16C550. The difference between the ST16C552 and ST16C552A is the logic state of the

printer port, INTP interrupt. The INTP interrupt is active high (logic 1) on the ST16C552 whereas INTP is active

low (logic 0) on the ST16C552A part when the interrupt latch mode is selected. The 552/552A is fabricated in an

advanced CMOS process with power down mode to reduce the power consumption. The 552A does not support

the power down mode.

INTB

INTP

-SLCTIN

INIT

-AUTOFDXT

-STROBE

GND

PD0

PD1

PD2

PD3

PD4

PD5

PD6

PD7

INTA

RDOUT

10

11

12

13

14

15

16

17

18

19

20

21

22

23

24

25

26

60

59

58

57

56

55

54

53

52

51

50

49

48

47

46

45

44

ST16C552CJ68

ST16C552ACJ68

TXB

-DTRB

-RTSB

-CTSB

D0

D1

D2

D3

D4

D5

D6

D7

-TXRDYA

VCC

-RTSA

-DTRA

TXA

FEATURES

Added features in device revision "F" and newer:

• 5V Tolerant Inputs

• Pin to pin and functional compatible to ST16C452/

452PS, TL16C552

• 2.97 to 5.5 volt operation

• Software compatible with INS8250, NS16C550

• 1.5 Mbps transmit/receive operation (24MHz)

• 16 byte transmit FIFO

• 16 byte receive FIFO with error flags

• Independent transmit and receive control

• Modem and printer status registers

• UART port and printer port Bi-directional

• Printer port direction set by single control bit or 8 bit

pattern (AA/55)

• Modem control signals (-CTS, -RTS, -DSR, -DTR,

-RI, -CD)

• Programmable character lengths (5, 6, 7, 8)

• Even, odd, or no parity bit generation and detection

• TTL compatible inputs, outputs

• Powerdownmode

ORDERING INFORMATION

Part number

Pins

Package

Operating temperature

Device Status

ST16C552CJ68

68

PLCC

0° C to + 70° C

Active

ST16C552ACJ68

68

PLCC

0° C to + 70° C

Active

ST16C552IJ68

68

PLCC

-40° C to + 85° C

Active

ST16C552AIJ68

68

PLCC

-40° C to + 85° C

Active