Datasheet

Table Of Contents
2010 Microchip Technology Inc. Preliminary DS39979A-page 267
PIC18F87J72 FAMILY
FIGURE 20-5: ASYNCHRONOUS RECEPTION
TABLE 20-5: REGISTERS ASSOCIATED WITH ASYNCHRONOUS RECEPTION
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 49
PIR3 LCDIF RC2IF TX2IF CTMUIF CCP2IF CCP1IF RTCCIF 52
PIE3 LCDIE RC2IE TX2IE CTMUIE CCP2IE CCP1IE RTCCIE 52
IPR3
LCDIP RC2IP TX2IP CTMUIP CCP2IP CCP1IP RTCCIP 52
RCSTA2 SPEN RX9 SREN CREN ADDEN FERR OERR RX9D 54
RCREG2 AUSART Receive Register 54
TXSTA2
CSRC TX9 TXEN SYNC —BRGHTRMT TX9D 54
SPBRG2 AUSART Baud Rate Generator Register 54
Legend: — = unimplemented locations read as ‘0’. Shaded cells are not used for asynchronous reception.
Start
bit
bit 7/8
bit 1bit 0 bit 7/8
bit 0Stop
bit
Start
bit
Start
bit
bit 7/8
Stop
bit
RX2 (pin)
Rcv Buffer Reg
Rcv Shift Reg
Read Rcv
Buffer Reg
RCREG2
RC2IF
(Interrupt Flag)
OERR bit
CREN
Word 1
RCREG2
Word 2
RCREG2
Stop
bit
Note: This timing diagram shows three words appearing on the RX2 input. The RCREG2 (Receive Buffer register) is read after the third word
causing the OERR (Overrun) bit to be set.