PIC18F1XK22 Datasheet, PDF (205/388 Pages) Microchip Technology – 20-Pin Flash Microcontrollers with nanoWatt XLP Technology

PIC18F1XK22/LF1XK22
15.4.2.3 EUSART Synchronous Slave
Reception
The operation of the Synchronous Master and Slave
modes is identical (Section 15.4.1.6 “Synchronous
Master Reception”), with the following exceptions:
• Sleep
• CREN bit is always set, therefore the receiver is
never Idle
• SREN bit, which is a “don't care” in Slave mode
A character may be received while in Sleep mode by
setting the CREN bit prior to entering Sleep. Once the
word is received, the RSR register will transfer the data
to the RCREG register. If the RCIE enable bit is set, the
interrupt generated will wake the device from Sleep
and execute the next instruction. If the GIE bit is also
set, the program will branch to the interrupt vector.
15.4.2.4 Synchronous Slave Reception
Set-up:
1. Set the SYNC and SPEN bits and clear the
CSRC bit. Set the TRIS bits corresponding to
the RX/DT and TX/CK I/O pins.
2. If using interrupts, ensure that the GIE and PEIE
bits of the INTCON register are set and set the
RCIE bit.
3. If 9-bit reception is desired, set the RX9 bit.
4. Set the CREN bit to enable reception.
5. The RCIF bit will be set when reception is
complete. An interrupt will be generated if the
RCIE bit was set.
6. If 9-bit mode is enabled, retrieve the Most
Significant bit from the RX9D bit of the RCSTA
register.
7. Retrieve the 8 Least Significant bits from the
receive FIFO by reading the RCREG register.
8. If an overrun error occurs, clear the error by
either clearing the CREN bit of the RCSTA
register or by clearing the SPEN bit which resets
the EUSART.
TABLE 15-10: REGISTERS ASSOCIATED WITH SYNCHRONOUS SLAVE RECEPTION
Name
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
BAUDCON ABDOVF RCIDL DTRXP CKTXP BRG16
—
WUE ABDEN
INTCON GIE/GIEH PEIE/GIEL TMR0IE INT0IE RABIE TMR0IF INT0IF RABIF
IPR1
—
ADIP
RCIP
TXIP SSPIP CCP1IP TMR2IP TMR1IP
PIE1
—
ADIE
RCIE
TXIE SSPIE CCP1IE TMR2IE TMR1IE
PIR1
—
ADIF
RCIF
TXIF SSPIF CCP1IF TMR2IF TMR1IF
RCREG
EUSART Receive Register
RCSTA
SPEN
RX9
SREN CREN ADDEN FERR OERR RX9D
SPBRG
EUSART Baud Rate Generator Register, Low Byte
SPBRGH EUSART Baud Rate Generator Register, High Byte
TXSTA
CSRC
TX9
TXEN SYNC SENDB BRGH TRMT TX9D
Legend: — = unimplemented, read as ‘0’. Shaded cells are not used for synchronous slave reception.
Reset
Values
on page
259
257
260
260
260
259
259
259
259
259
 2010 Microchip Technology Inc.
Preliminary
DS41365D-page 205