Datasheet

Table Of Contents
PIC18F85J90 FAMILY
DS39770C-page 248 2010 Microchip Technology Inc.
FIGURE 18-7: ASYNCHRONOUS RECEPTION
TABLE 18-6: 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 57
PIR1 ADIF RC1IF TX1IF SSPIF TMR2IF TMR1IF 60
PIE1 ADIE RC1IE TX1IE SSPIE TMR2IE TMR1IE 60
IPR1
ADIP RC1IP TX1IP SSPIP TMR2IP TMR1IP 60
RCSTA1 SPEN RX9 SREN CREN ADDEN FERR OERR RX9D 59
RCREG1 EUSART Receive Register 59
TXSTA1
CSRC TX9 TXEN SYNC SENDB BRGH TRMT TX9D 59
BAUDCON1 ABDOVF RCIDL RXDTP TXCKP BRG16 WUE ABDEN 61
SPBRGH1 EUSART Baud Rate Generator Register High Byte 61
SPBRG1 EUSART Baud Rate Generator Register Low Byte 59
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
RX1 (pin)
Rcv Buffer Reg
Rcv Shift Reg
Read Rcv
Buffer Reg
RCREG1
RC1IF
(Interrupt Flag)
OERR bit
CREN bit
Word 1
RCREG1
Word 2
RCREG1
Stop
bit
Note: This timing diagram shows three words appearing on the RX1 input. The RCREG1 (Receive Buffer register) is read after the third word
causing the OERR (Overrun) bit to be set.