Datasheet

© 2009-2012 Microchip Technology Inc. Preliminary DS70616F-page 337
dsPIC33EPXXX(GP/MC/MU)806/810/814 and PIC24EPXXX(GP/GU)810/814
18.3 SPI Control Registers
REGISTER 18-1: SPIxSTAT: SPIx STATUS AND CONTROL REGISTER
R/W-0 U-0 R/W-0 U-0 U-0 R/W-0 R/W-0 R/W-0
SPIEN
—SPISIDL — — SPIBEC<2:0>
bit 15 bit 8
R/W-0 R/C-0, HS R/W-0 R/W-0 R/W-0 R/W-0 R-0, HS, HC R-0, HS, HC
SRMPT SPIROV SRXMPT SISEL<2:0> SPITBF SPIRBF
bit 7 bit 0
Legend: C = Clearable bit
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
HS = Set in Hardware bit HC = Cleared in Hardware bit U = Unimplemented bit, read as ‘0’
bit 15 SPIEN: SPIx Enable bit
1 = Enables the module and configures SCKx, SDOx, SDIx and SSx
as serial port pins
0 = Disables the module
bit 14 Unimplemented: Read as ‘0’
bit 13 SPISIDL: Stop in Idle Mode bit
1 = Discontinue the module operation when device enters Idle mode
0 = Continue the module operation in Idle mode
bit 12-11 Unimplemented: Read as ‘0’
bit 10-8 SPIBEC<2:0>: SPIx Buffer Element Count bits (valid in Enhanced Buffer mode)
Master mode:
Number of SPIx transfers are pending.
Slave mode:
Number of SPIx transfers are unread.
bit 7 SRMPT: Shift Register (SPIxSR) Empty bit (valid in Enhanced Buffer mode)
1 = SPIx Shift register is empty and ready to send or receive the data
0 = SPIx Shift register is not empty
bit 6 SPIROV: Receive Overflow Flag bit
1
= A new byte/word is completely received and discarded. The user application has not read the previous
data in the SPIxBUF register
0 = No overflow has occurred
bit 5 SRXMPT: Receive FIFO Empty bit (valid in Enhanced Buffer mode)
1 = RX FIFO is empty
0 = RX FIFO is not empty
bit 4-2 SISEL<2:0>: SPIx Buffer Interrupt Mode bits (valid in Enhanced Buffer mode)
111 = Interrupt when the SPIx transmit buffer is full (SPIxTBF bit is set)
110 = Interrupt when last bit is shifted into SPIxSR, and as a result, the TX FIFO is empty
101 = Interrupt when the last bit is shifted out of SPIxSR, and the transmit is complete
100 = Interrupt when one data is shifted into the SPIxSR, and as a result, the TX FIFO has one open
memory location
011 = Interrupt when the SPIx receive buffer is full (SPIxRBF bit set)
010 = Interrupt when the SPIx receive buffer is 3/4 or more full
001 = Interrupt when data is available in the receive buffer (SRMPT bit is set)
000 = Interrupt when the last data in the receive buffer is read, as a result, the buffer is empty
(SRXMPT bit set)