PIC16F688
To set up a Synchronous Slave Reception:
10.5.2
USART 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, then a word may be received. 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 chip from Sleep. 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 10-10: REGISTERS ASSOCIATED WITH SYNCHRONOUS SLAVE RECEPTION
Value on
all other
Resets
Value on
POR, BOD
Addr
Name
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
0Ch PIR1
EEIF
ADIF
RCIF
—
C2IF
C1IF
OSFIF
—
TXIF
WUE
TMR1IF 0000 0000
ABDEN 00-0 0-00
0000 0000
0000 0000
00-0 0-00
0000 0000
0000 0000
0000 0000
0000 0000
0000 0010
0000 000X
0000 0000
11h BAUDCTL ABDOVF RCIDL
SCKP BRG16
12h SPBRGH USART Baud Rate High Generator
13h SPBRG
14h RCREG
15h TXREG
16h TXSTA
17h RCSTA
8Ch PIE1
USART Baud Rate Generator
USART Receive Register
USART Transmit Register
0000 0000
0000 0000
0000 0000
CSRC
SPEN
EEIE
TX9
RX9
ADIE
TXEN
SREN CREN ADDEN FERR
RCIE C2IE C1IE OSFIE
SYNC SENDB BRGH TRMT
TX9D
RX9D
0000 0010
0000 000X
OERR
TXIE
TMR1IE 0000 0000
Legend:
x= unknown, - = unimplemented locations read as ‘0’. Shaded cells are not used for Asynchronous Reception.
DS41203B-page 98
Preliminary
2004 Microchip Technology Inc.
MICROCHIP [ MICROCHIP ]
