PIC18F2221 MICROCHIP [Microchip Technology], PIC18F2221 Datasheet - Page 218

• Manufacturer Part Number: PIC18F2221
• Description: 28/40/44-Pin Enhanced Flash Microcontrollers with 10-Bit A/D and nanoWatt Technology
• Manufacturer: MICROCHIP [Microchip Technology]

PIC18F4321 FAMILY
FIGURE 18-3:
FIGURE 18-4:
FIGURE 18-5:
DS39689E-page 216
Note: This timing diagram shows two consecutive transmissions.
(Interrupt Reg. Flag)
Reg. Empty Flag)
Reg. Empty Flag)
Write to TXREG
(Transmit Buffer
Reg. Empty Flag)
(Transmit Shift
Write to TXREG
(Transmit Shift
BRG Output
(Shift Clock)
BRG Output
(Shift Clock)
TRMT bit
TX (pin)
TXIF bit
TRMT bit
BRG16
TX (pin)
TXIF bit
TXIE
Interrupt
1 T
EUSART TRANSMIT BLOCK DIAGRAM
ASYNCHRONOUS TRANSMISSION, TXCKP = 0 (TX NOT INVERTED)
ASYNCHRONOUS TRANSMISSION (BACK TO BACK),
TXCKP = 0 (TX NOT INVERTED)
SPBRGH
Baud Rate Generator
CY
TXIF
Word 1
Transmit Shift Reg
TXEN
Transmit Shift Reg.
Word 1
Word 1
Word 1
Baud Rate CLK
1 T
SPBRG
CY
Start bit
Start bit
Word 2
MSb
(8)
1 T
CY
bit 0
bit 0
Preliminary
TXREG Register
TSR Register
TX9D
• • •
bit 1
TX9
8
Data Bus
Word 1
bit 1
Word 1
LSb
0
TRMT
bit 7/8
bit 7/8
and Control
Pin Buffer
TXCKP
Word 2
Transmit Shift Reg.
Stop bit
© 2007 Microchip Technology Inc.
SPEN
Stop bit
Start bit
Word 2
TX pin
bit 0