Datasheet

Table Of Contents
PIC18F1220/1320
DS39605F-page 142 © 2007 Microchip Technology Inc.
FIGURE 16-4: ASYNCHRONOUS TRANSMISSION (BACK TO BACK)
TABLE 16-5: REGISTERS ASSOCIATED WITH ASYNCHRONOUS TRANSMISSION
Transmit Shift Reg.
Write to TXREG
BRG Output
(Shift Clock)
RB1/AN5/TX/
TXIF bit
(Interrupt Reg. Flag)
TRMT bit
(Transmit Shift
Reg. Empty Flag)
Word 1
Word 2
Word 1
Word 2
Stop bit
Start bit
Transmit Shift Reg.
Word 1
Word 2
bit 0 bit 1
bit 7/8 bit 0
Note: This timing diagram shows two consecutive transmissions.
1 TCY
1 TCY
CK/INT1 (pin)
Start bit
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 GIE/GIEH PEIE/GIEL
TMR0IE INT0IE RBIE TMR0IF INT0IF RBIF 0000 000x 0000 000u
PIR1
ADIF RCIF TXIF CCP1IF TMR2IF TMR1IF -000 -000 -000 -000
PIE1
ADIE RCIE TXIE CCP1IE TMR2IE TMR1IE -000 -000 -000 -000
IPR1
ADIP RCIP TXIP CCP1IP TMR2IP TMR1IP -111 -111 -111 -111
RCSTA
SPEN RX9 SREN CREN ADDEN FERR OERR RX9D 0000 -00x 0000 -00x
TXREG
EUSART Transmit Register 0000 0000 0000 0000
TXSTA
CSRC TX9 TXEN SYNC SENDB BRGH TRMT TX9D 0000 0010 0000 0010
BAUDCTL
RCIDL SCKP BRG16 WUE ABDEN -1-1 0-00 -1-1 0-00
SPBRGH Baud Rate Generator Register High Byte 0000 0000 0000 0000
SPBRG Baud Rate Generator Register Low Byte 0000 0000 0000 0000
Legend: x = unknown, – = unimplemented locations read as ‘0’. Shaded cells are not used for asynchronous transmission.