beautypg.com

FUJITSU MB91F109 FR30 User Manual

Page 271

background image

247

10.1 Overview of UART

UART Block Diagram

Figure 10.1-2 is a UART block diagram.

Figure 10.1-2 UART Block Diagram

SC

SI

SO

SIDR

SODR

MD1

PEN

PE

MD0

P

ORE

SBL

FRE

SMR

SCR

CL

SSR

RDRF

CS0

A/D

TDRE

REC

SCKE

RXE

RIE

SOE

TXE

TIE

R - BUS

Control signal

Reception interrupt

(to CPU)

From U-TIMER

External clock

Clock

selection

circuit

Reception clock

Transmission clock

SC (clock)

Transmision interrupt

(to CPU)

(received data)

Reception

control circuit

Start bit

detection circuit

Reception
bit counter

Reception

parity counter

Transmission

control circuit

Tranmission
start circuit

Tranmission

bit counter

Tranmission
parity counter

(Transmit data)

Reception status

check circuit

Reception shifter

End of reception

Transmission shifter

Start of transmission

Reception error generation

signal for DMA (to DMAC)

register

register

register

Control signal