PIC16F870-I/SP View Datasheet(PDF) - Microchip Technology

Part Name

Description

Manufacturer

PIC16F870-I/SP

28/40-Pin, 8-Bit CMOS FLASH Microcontrollers

Microchip Technology 

PIC16F870/871

FIGURE 9-7: ASYNCHRONOUS RECEPTION WITH ADDRESS DETECT

RC7/RX/DT (pin)

Start

bit bit0 bit1

Start

bit8 Stop bit bit0

bit

bit8 Stop

bit

Load RSR

Read

Bit8 = 0, Data Byte

Bit8 = 1, Address Byte

WORD 1

RCREG

RCIF

Note: This timing diagram shows a data byte followed by an address byte. The data byte is not read into the RCREG

(receive buffer) because ADDEN = 1.

FIGURE 9-8: ASYNCHRONOUS RECEPTION WITH ADDRESS BYTE FIRST

RC7/RX/DT (pin)

Start

bit bit0 bit1

Start

bit8 Stop bit bit0

bit

bit8 Stop

bit

Load RSR

Read

Bit8 = 1, Address Byte

Bit8 = 0, Data Byte

WORD 1

RCREG

RCIF

Note: This timing diagram shows a data byte followed by an address byte. The data byte is not read into the RCREG

(receive buffer) because ADDEN was not updated and still = 0.

TABLE 9-7: REGISTERS ASSOCIATED WITH ASYNCHRONOUS RECEPTION

Address Name

Bit 7

Bit 6 Bit 5 Bit 4 Bit 3

Bit 2

Bit 1

Bit 0

Value on:

POR,

BOR

Value on

all other

Resets

0Ch

PIR1

PSPIF(1) ADIF RCIF TXIF

— CCP1IF TMR2IF TMR1IF 0000 -000 0000 -000

18h

RCSTA SPEN

RX9 SREN CREN ADDEN FERR OERR RX9D 0000 000x 0000 000x

1Ah

RCREG USART Receive Register

0000 0000 0000 0000

8Ch

PIE1

PSPIE(1) ADIE RCIE TXIE

— CCP1IE TMR2IE TMR1IE 0000 -000 0000 -000

98h

TXSTA

CSRC

TX9 TXEN SYNC — BRGH TRMT TX9D 0000 -010 0000 -010

99h

SPBRG Baud Rate Generator Register

0000 0000 0000 0000

Legend: x = unknown, - = unimplemented locations read as '0'. Shaded cells are not used for Asynchronous Reception.

Note 1: Bits PSPIE and PSPIF are reserved on the PIC16F870; always maintain these bits clear.

DS30569A-page 72

Preliminary

© 1999 Microchip Technology Inc.

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