PIC16F882-I Datasheet, PDF (178/328 Pages) Microchip Technology – 28/40/44-Pin, Enhanced Flash-Based 8-Bit CMOS Microcontrollers

PIC16F882/883/884/886/887
12.4.2.3 EUSART Synchronous Slave
Reception
The operation of the Synchronous Master and Slave
modes is identical (Section 12.4.1.5 “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.
12.4.2.4 Synchronous Slave Reception Set-
up:
1. Set the SYNC and SPEN bits and clear the
CSRC bit.
2. If interrupts are desired, set the RCIE bit of the
PIE1 register and the GIE and PEIE bits of the
INTCON register.
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 12-10: REGISTERS ASSOCIATED WITH SYNCHRONOUS SLAVE RECEPTION
Name
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Value on
POR, BOR
Value on
all other
Resets
BAUDCTL ABDOVF RCIDL
—
SCKP BRG16
—
WUE ABDEN 01-0 0-00 01-0 0-00
INTCON
GIE
PEIE
T0IE
INTE
RBIE
T0IF
INTF
RBIF 0000 000x 0000 000x
PIE1
—
ADIE
RCIE
TXIE SSPIE CCP1IE TMR2IE TMR1IE -000 0000 -000 0000
PIR1
—
ADIF
RCIF
TXIF SSPIF CCP1IF TMR2IF TMR1IF -000 0000 -000 0000
RCREG EUSART Receive Data Register
0000 0000 0000 0000
RCSTA
SPEN
RX9
SREN CREN ADDEN FERR OERR RX9D 0000 000x 0000 000x
SPBRG
BRG7 BRG6 BRG5 BRG4 BRG3 BRG2 BRG1 BRG0 0000 0000 0000 0000
SPBRGH BRG15 BRG14 BRG13 BRG12 BRG11 BRG10 BRG9 BRG8 0000 0000 0000 0000
TRISC
TRISC7 TRISC6 TRISC5 TRISC4 TRISC3 TRISC2 TRISC1 TRISC0 1111 1111 1111 1111
TXREG EUSART Transmit Data Register
0000 0000 0000 0000
TXSTA
CSRC
TX9
TXEN SYNC SENDB BRGH TRMT TX9D 0000 0010 0000 0010
Legend: x = unknown, – = unimplemented read as ‘0’. Shaded cells are not used for Synchronous Slave Reception.
DS41291F-page 176
© 2009 Microchip Technology Inc.