Philips SC28L91 User Manual

Page 6

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Philips Semiconductors

Product data sheet

SC28L91

3.3 V or 5.0 V Universal Asynchronous
Receiver/Transmitter (UART)

2004 Oct 21

6

8

D0–D7

RDN

WRN

CEN

A0–A3

RESET

INTRN

X1/CLK

X2

4

BUS BUFFER

OPERATION CONTROL

ADDRESS

DECODE

R/W CONTROL

INTERRUPT CONTROL

IMR

ISR

TIMING

BAUD RATE

GENERATOR

CLOCK

SELECTORS

COUNTER/

TIMER

XTAL OSC

CSR

ACR

CTL

DATA CHANNEL

16 BYTE TRANSMIT

FIFO

TRANSMIT

SHIFT REGISTER

16 BYTE RECEIVE

FIFO

MRA0, 1, 2

CRA

SRA

INPUT PORT

CHANGE OF

STATE

DETECTORS (4)

OUTPUT PORT

FUNCTION

SELECT LOGIC

OPCR

TxDA

RxDA

IP0-IP6

OP0-OP7

V

CC

V

SS

CONTROL

TIMING

INTERNAL

DA

T

ABUS

IPCR

ACR

OPR

CTU

8

7

WATCH DOG TIMER

RECEIVE SHIFT

REGISTER

SD00702

GP

Figure 1. Block Diagram (80XXX mode)