Microchip Technology ARD00385 Data Sheet

PIC18F87K90 FAMILY

DS39957D-page 358

 2009-2011 Microchip Technology Inc.

FIGURE 22-1:

AUTOMATIC BAUD RATE CALCULATION

FIGURE 22-2:

BRG OVERFLOW SEQUENCE

BRG Value

RXx Pin

ABDEN bit

RCxIF bit

Bit 0

Bit 1

(Interrupt)

Read

RCREGx

BRG Clock

Start

Auto-Cleared

Set by User

XXXXh

0000h

Edge #1

Bit 2

Bit 3

Edge #2

Bit 4

Bit 5

Edge #3

Bit 6

Bit 7

Edge #4

001Ch

Note:

The ABD sequence requires the EUSART module to be configured in Asynchronous mode and WUE = 0.

SPBRGx

XXXXh

1Ch

SPBRGHx

XXXXh

00h

Edge #5

Stop Bit

Start

Bit 0

XXXXh

0000h

FFFFh

BRG Clock

ABDEN bit

RXx Pin

ABDOVF bit

BRG Value