PIC16F877ATISLASHML datasheet(121/234 Pages) MICROCHIP

121 / 234 page

 2003 Microchip Technology Inc.

DS39582B-page 119

PIC16F87XA

10.2.3

SETTING UP 9-BIT MODE WITH

ADDRESS DETECT

When setting up an Asynchronous Reception with

address detect enabled:

• Initialize the SPBRG register for the appropriate

baud rate. If a high-speed baud rate is desired,

set bit BRGH.

• Enable the asynchronous serial port by clearing

bit SYNC and setting bit SPEN.

• If interrupts are desired, then set enable bit RCIE.

• Set bit RX9 to enable 9-bit reception.

• Set ADDEN to enable address detect.

• Enable the reception by setting enable bit CREN.

• Flag bit RCIF will be set when reception is

complete, and an interrupt will be generated if

enable bit RCIE was set.

• Read the RCSTA register to get the ninth bit and

determine if any error occurred during reception.

• Read the 8-bit received data by reading the

RCREG register to determine if the device is

being addressed.

• If any error occurred, clear the error by clearing

enable bit CREN.

• If the device has been addressed, clear the

ADDEN bit to allow data bytes and address bytes

to be read into the receive buffer and interrupt the

CPU.

FIGURE 10-6:

USART RECEIVE BLOCK DIAGRAM

x64 Baud Rate CLK

SPBRG

Baud Rate Generator

RC7/RX/DT

Pin Buffer

and Control

SPEN

Data

Recovery

CREN

OERR

FERR

RSR Register

MSb

LSb

RX9D

RCREG Register

FIFO

Interrupt

RCIF

RCIE

Data Bus

÷ 64

÷ 16

Stop

Start

(8)

RX9

• • •

RX9

ADDEN

RX9

ADDEN

RSR<8>

Enable

Load of

Receive

Buffer

FOSC

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