PIC16F648ATEML View Datasheet(PDF) - Microchip Technology

Part Name

Description

Manufacturer

PIC16F648ATEML

Flash-Based, 8-Bit CMOS Microcontrollers with nanoWatt Technology

Microchip Technology 

PIC16F627A/628A/648A

FIGURE 12-5:

ASYNCHRONOUS RECEPTION WITH ADDRESS DETECT

RB1/RX/DT (Pin)

RCV Shift Reg

Start

bit bit 0 bit 1

Start

bit 8 Stop bit bit 0

bit

bit 8 Stop

bit

RCV Buffer Reg

Read RCV

Buffer Reg

RCREG

bit 8 = 0, Data Byte

bit 8 = 1, Address Byte

Word 1

RCREG

RCIF

(interrupt flag)

ADEN = 1

‘1’

‘1’

(Address Match

Enable)

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 ADEN = 1 and bit 8 = 0.

FIGURE 12-6:

ASYNCHRONOUS RECEPTION WITH ADDRESS BYTE FIRST

RB1/RX/DT (pin)

RCV Shift Reg

RCV Buffer Reg

Read RCV

Buffer Reg

RCREG

Start

bit bit 0 bit 1

Start

bit 8 Stop bit bit 0

bit

bit 8 Stop

bit

bit 8 = 1, Address Byte

Word 1

RCREG

bit 8 = 0, Data Byte

RCIF

(Interrupt Flag)

ADEN = 1

‘1’

‘1’

(Address Match

Enable)

Note:

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

(receive buffer) because ADEN was not updated (still = 1) and bit 8 = 0.

FIGURE 12-7:

RB1/RX/DT (pin)

RCV Shift

Reg

RCV Buffer Reg

Read RCV

Buffer Reg

RCREG

RCIF

(Interrupt Flag)

ADEN

(Address Match

Enable)

ASYNCHRONOUS RECEPTION WITH ADDRESS BYTE FIRST FOLLOWED BY

VALID DATA BYTE

Start

bit bit 0 bit 1

Start

bit 8 Stop bit bit 0

bit

bit 8 Stop

bit

bit 8 = 1, Address Byte

Word 1 bit 8 = 0, Data Byte

RCREG

Word 2

RCREG

Note:

This timing diagram shows an address byte followed by an data byte. The data byte is read into the RCREG

(Receive Buffer) because ADEN was updated after an address match, and was cleared to a ‘0’, so the contents

of the Receive Shift Register (RSR) are read into the Receive Buffer regardless of the value of bit 8.

© 2007 Microchip Technology Inc.

DS40044F-page 81

Share Link: