PIC16F946 Datasheet, PDF (140/274 Pages) Microchip Technology – 64-Pin Flash-Based, 8-Bit CMOS Microcontrollers with LCD Driver and nanoWatt Technology

PIC16F946
FIGURE 11-1:
USART TRANSMIT BLOCK DIAGRAM
TXIE
TXIF
Interrupt
MSb
(8)
Data Bus
TXREG Register
8
•••
TSR Register
TXEN Baud Rate CLK
SPBRG
LSb
0
Pin Buffer
and Control
RC6/TX/CK/SCK/
SCL/SEG9 pin
TRMT
SPEN
Baud Rate Generator
TX9
TX9D
FIGURE 11-2:
Write to TXREG
BRG Output
(Shift Clock)
RC6/TX/CK/
SCK/SCL/SEG9
TXIF bit
(Transmit Buffer
Reg. Empty Flag)
ASYNCHRONOUS MASTER TRANSMISSION
Word 1
Start bit
bit 0
bit 1
Word 1
TRMT bit
(Transmit Shift
Reg. Empty Flag)
Word 1
Transmit Shift Reg
bit 7/8 _{Stop bit}
FIGURE 11-3:
ASYNCHRONOUS MASTER TRANSMISSION (BACK-TO-BACK)
Write to TXREG
BRG Output
(Shift Clock)
RC6/TX/CK/
SCK/SCL/SEG9
TXIF bit
(Interrupt Reg. Flag)
Word 1 Word 2
Start bit
bit 0
bit 1
Word 1
bit 7/8 _{Stop bit}
Start bit
bit 0
Word 2
TRMT bit
(Transmit Shift
Reg. Empty Flag)
Word 1
Transmit Shift Reg.
Word 2
Transmit Shift Reg.
Note: This timing diagram shows two consecutive transmissions.
DS41265A-page 138
Preliminary
© 2005 Microchip Technology Inc.