PIC18F2331/2431/4331/4431
To set up a Synchronous Slave Reception:
20.5.2
EUSART SYNCHRONOUS SLAVE
RECEPTION
1. Enable the synchronous master serial port by
setting bits, SYNC and SPEN, and clearing bit,
CSRC.
The operation of the Synchronous Master and Slave
modes is identical, except in the case of Sleep, or any
Idle mode and bit SREN, which is a “don’t care” in
Slave mode.
2. If interrupts are desired, set enable bit, RCIE.
3. If 9-bit reception is desired, set bit, RX9.
4. To enable reception, set enable bit, CREN.
If receive is enabled by setting the CREN bit prior to
entering Sleep or any Idle mode, then a word may be
received while in this Low-Power mode. Once the word
is received, the RSR register will transfer the data to the
RCREG register. If the RCIE enable bit is set, the inter-
rupt generated will wake the chip from Low-Power
mode. If the global interrupt is enabled, the program will
branch to the interrupt vector.
5. Flag bit, RCIF, will be set when reception is
complete. An interrupt will be generated if
enable bit, RCIE, was set.
6. Read the RCSTA register to get the 9th bit (if
enabled) and determine if any error occurred
during reception.
7. Read the 8-bit received data by reading the
RCREG register.
8. If any error occurred, clear the error by clearing
bit, CREN.
9. If using interrupts, ensure that the GIE and PEIE
bits in the INTCON register (INTCON<7:6>) are
set.
TABLE 20-10: REGISTERS ASSOCIATED WITH SYNCHRONOUS SLAVE RECEPTION
Reset Values
on Page:
Name
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
INTCON
PIR1
GIE/GIEH PEIE/GIEL TMR0IE INT0IE
RBIE
TMR0IF INT0IF
RBIF
54
57
57
57
56
56
56
56
56
56
—
—
ADIF
ADIE
ADIP
RX9
RCIF
RCIE
RCIP
SREN
TXIF
TXIE
TXIP
SSPIF CCP1IF TMR2IF TMR1IF
SSPIE CCP1IE TMR2IE TMR1IE
SSPIP CCP1IP TMR2IP TMR1IP
PIE1
IPR1
—
RCSTA
RCREG
TXSTA
BAUDCON
SPBRGH
SPBRG
SPEN
CREN ADDEN FERR
OERR
RX9D
EUSART Receive Register
CSRC
—
TX9
TXEN
—
SYNC SENDB BRGH
TRMT
WUE
TX9D
RCIDL
SCKP BRG16
—
ABDEN
EUSART Baud Rate Generator Register High Byte
EUSART Baud Rate Generator Register Low Byte
Legend: — = unimplemented, read as ‘0’. Shaded cells are not used for synchronous slave reception.
DS39616D-page 238
2010 Microchip Technology Inc.
MICROCHIP [ MICROCHIP ]
