Datasheet

Table Of Contents
2010 Microchip Technology Inc. DS39933D-page 281
PIC18F87J90 FAMILY
FIGURE 20-2: ASYNCHRONOUS TRANSMISSION
FIGURE 20-3: ASYNCHRONOUS TRANSMISSION (BACK TO BACK)
TABLE 20-4: REGISTERS ASSOCIATED WITH ASYNCHRONOUS TRANSMISSION
Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0
Reset
Values
on Page
INTCON GIE/GIEH PEIE/GIEL
TMR0IE INT0IE RBIE TMR0IF INT0IF RBIF 59
PIR3
LCDIF RC2IF TX2IF CTMUIF CCP2IF CCP1IF RTCCIF 62
PIE3 LCDIE RC2IE TX2IE CTMUIE CCP2IE CCP1IE RTCCIE 62
IPR3
LCDIP RC2IP TX2IP CTMUIP CCP2IP CCP1IP RTCCIP 62
RCSTA2
SPEN RX9 SREN CREN ADDEN FERR OERR RX9D 64
TXREG2 AUSART Transmit Register 64
TXSTA2
CSRC TX9 TXEN SYNC BRGH TRMT TX9D 64
SPBRG2 AUSART Baud Rate Generator Register 64
LATG U2OD
U1OD LATG4 LATG3 LATG2 LATG1 LATG0 62
Legend: — = unimplemented locations read as ‘0’. Shaded cells are not used for asynchronous transmission.
Word 1
Word 1
Transmit Shift Reg
Start bit bit 0 bit 1 bit 7/8
Write to TXREG2
BRG Output
(Shift Clock)
TX2 (pin)
TX2IF bit
(Transmit Buffer
Reg. Empty Flag)
TRMT bit
(Transmit Shift
Reg. Empty Flag)
1 TCY
Word 1
Stop bit
Transmit Shift Reg.
Write to TXREG2
BRG Output
(Shift Clock)
TX2 (pin)
TX2IF 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
Start bit