Datasheet

 2011-2013 Microchip Technology Inc. DS40001574C-page 313
PIC16(L)F1938/9
25.5.2.3 EUSART Synchronous Slave
Reception
The operation of the Synchronous Master and Slave
modes is identical (
Section 25.5.1.5 “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.
25.5.2.4 Synchronous Slave Reception
Set-up:
1. Set the SYNC and SPEN bits and clear the
CSRC bit.
2. Clear the ANSEL bit for both the CK and DT pins
(if applicable).
3. If interrupts are desired, set the RCIE bit of the
PIE1 register and the GIE and PEIE bits of the
INTCON register.
4. If 9-bit reception is desired, set the RX9 bit.
5. Set the CREN bit to enable reception.
6. The RCIF bit will be set when reception is
complete. An interrupt will be generated if the
RCIE bit was set.
7. If 9-bit mode is enabled, retrieve the Most
Significant bit from the RX9D bit of the RCSTA
register.
8. Retrieve the eight Least Significant bits from the
receive FIFO by reading the RCREG register.
9. 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 25-10: SUMMARY OF REGISTERS ASSOCIATED WITH SYNCHRONOUS SLAVE
RECEPTION
Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0
Register
on Page
BAUDCON ABDOVF RCIDL —SCKPBRG16 — WUE ABDEN
298
INTCON GIE PEIE
TMR0IE INTE IOCIE TMR0IF INTF IOCIF
90
PIE1
TMR1GIE ADIE RCIE TXIE SSPIE CCP1IE TMR2IE TMR1IE
91
PIR1
TMR1GIF ADIF RCIF TXIF SSPIF CCP1IF TMR2IF TMR1IF
94
RCREG EUSART Receive Data Register
292*
RCSTA SPEN
RX9 SREN CREN ADDEN FERR OERR RX9D
297
TRISC TRISC7 TRISC6
TRISC5 TRISC4 TRISC3 TRISC2 TRISC1 TRISC0
134
TXSTA CSRC TX9 TXEN SYNC
SENDB BRGH TRMT TX9D
296
Legend: — = unimplemented read as ‘0’. Shaded cells are not used for Synchronous Slave Reception.
* Page provides register information.