PIC18F2220 Datasheet, PDF (205/388 Pages) Microchip Technology – 28/40/44-Pin High-Performance, Enhanced Flash Microcontrollers with 10-Bit A/D and nanoWatt Technology

PIC18F2220/2320/4220/4320
FIGURE 18-2:
Write to TXREG
BRG Output
(Shift Clock)
RC6/TX/CK (pin)
TXIF bit
(Transmit Buffer
Reg. Empty Flag)
ASYNCHRONOUS TRANSMISSION
Word 1
Start bit
bit 0
1 TCY
bit 1
Word 1
TRMT bit
(Transmit Shift
Reg. Empty Flag)
Word 1
Transmit Shift Reg
bit 7/8 _{Stop bit}
FIGURE 18-3:
Write to TXREG
BRG Output
(Shift Clock)
RC6/TX/CK (pin)
TXIF bit
(Interrupt Reg. Flag)
TRMT bit
(Transmit Shift
Reg. Empty Flag)
ASYNCHRONOUS TRANSMISSION (BACK TO BACK)
Word 1
Word 2
1 TCY
Start bit
Word 1
Transmit Shift Reg.
bit 0
1 TCY
bit 1
Word 1
bit 7/8 Stop bit
Start bit
bit 0
Word 2
Word 2
Transmit Shift Reg.
Note: This timing diagram shows two consecutive transmissions.
TABLE 18-6: REGISTERS ASSOCIATED WITH ASYNCHRONOUS TRANSMISSION
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
INTCON
PIR1
PIE1
IPR1
GIE/GIEH
PSPIF⁽¹⁾
PSPIE⁽¹⁾
PSPIP⁽¹⁾
PEIE/GIEL TMR0IE INT0IE
ADIF RCIF TXIF
ADIE RCIE TXIE
ADIP RCIP TXIP
RBIE
SSPIF
SSPIE
SSPIP
TMR0IF INT0IF
CCP1IF TMR2IF
CCP1IE TMR2IE
CCP1IP TMR2IP
RBIF
TMR1IF
TMR1IE
TMR1IP
0000 000x 0000 000u
0000 0000 0000 0000
0000 0000 0000 0000
1111 1111 1111 1111
RCSTA SPEN
RX9 SREN CREN ADDEN FERR OERR RX9D 0000 -00x 0000 -00x
TXREG USART Transmit Register
0000 0000 0000 0000
TXSTA CSRC
TX9 TXEN SYNC — BRGH TRMT TX9D 0000 -010 0000 -010
SPBRG Baud Rate Generator Register
0000 0000 0000 0000
Legend: x = unknown, - = unimplemented locations read as ‘0’. Shaded cells are not used for asynchronous transmission.
Note 1: The PSPIF, PSPIE and PSPIP bits are reserved on the PIC18F2X20 devices; always maintain these bits clear.
 2003 Microchip Technology Inc.
DS39599C-page 203