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Deserial Serial Peripheral Interface (DSPI)
MPC5644A Microcontroller Reference Manual, Rev. 6
Freescale Semiconductor
1317
The PCS switchover occurs at driving edge of the SCK clock output.
The second Data Selection Bit is inserted after the PCS switchover if enabled.
Data Frame with PCS switchover is shown in
.
Figure 30-52. TSB data frame format for MSC dual receiver operation
30.9.9
Parity generation and check
The DSPI module can generate and check parity in the serial frame. The parity bit replaces the last
transmitted bit in the frame. The parity is calculated for all transmitted data bits in frame, not including the
last, would be transmitted, data bit. The parity generation/control is done on frame basis. The registers
fields, setting frame size defines the total number of bits in the frame, including the parity bit. Thus, to
transmit/receive the same number of data bits with parity check, increase the frame size by one versus the
same data size frame without the parity check.
Parity can be selected as odd or even. Parity Errors in the received frame set Parity Error flags in the Status
register. The Parity Error Interrupt Requests are generated if enabled. The DSPI module can be
programmed to stop SPI or/and DSI frame transmission in case of a frame reception with parity error.
30.9.9.1
Parity for SPI frames
When the DSPI is in the master mode the parity generation is controlled by PE and PP bits of the TX FIFO
entries (DSPI_PUSHR). Setting the PE bit enables parity generation for transmitted SPI frames and parity
check for received frames. PP bit defines polarity of the parity bit.
When continuous PCS selection is used to transmit SPI data, two parity generation scenarios are available:
•
Generate/check parity for the whole frame
•
Generate/check parity for each subframe separately.
To generate/check parity for the whole frame set PE bit only in the last command/TX FIFO entry, forming
this frame (with the DSPI_PUSHR).
SCK
PCS0
SOUT
Data Sub frame 1
t
DT
Invalid
LSB
0
0
Data Selection Bits
Data Frame = 4 to 34 bits
PCS1
Data Sub frame 2
DSPI_CTARn[FMSZ] + 1
TSBCNT - FMSZ
Summary of Contents for MPC5644A
Page 2: ...MPC5644A Microcontroller Reference Manual Rev 6 2 Freescale Semiconductor...
Page 24: ...MPC5644A Microcontroller Reference Manual Rev 6 24 Freescale Semiconductor...
Page 26: ...MPC5644A Microcontroller Reference Manual Rev 6 26 Freescale Semiconductor...
Page 52: ...Introduction MPC5644A Microcontroller Reference Manual Rev 6 52 Freescale Semiconductor...
Page 56: ...Memory Map MPC5644A Microcontroller Reference Manual Rev 6 56 Freescale Semiconductor...
Page 1228: ...Decimation Filter MPC5644A Microcontroller Reference Manual Rev 6 1228 Freescale Semiconductor...
Page 1440: ...FlexCAN Module MPC5644A Microcontroller Reference Manual Rev 6 1440 Freescale Semiconductor...