Deserial – Serial Peripheral Interface (DSPI)
PXN20 Microcontroller Reference Manual, Rev. 1
Freescale Semiconductor 30-19
30.3.2.6 DSPI PUSH TX FIFO Register (DSPI_PUSHR)
The DSPI_PUSHR provides a means to write to the TX FIFO. Data written to this register is transferred 
to the TX FIFO. See Section 30.4.3.4, Transmit First-In First-Out (TX FIFO) Buffering Mechanism, for 
more information. Write accesses of 8 or 16 bits to the DSPI_PUSHR transfer 32 bits to the TX FIFO.
NOTE
Only the TXDATA field is used for DSPI slaves. 
NOTE
When the DSPI module has more than one entry in the TX FIFO and only 
one entry is written and that entry has the CONT bit set, and continuous 
SCK clock selected the PCS levels may change between transfer complete 
and write of the next data to the DSPI_PUSHR register. To ensure PCS 
stability during data transmission in Continious Selection Format and 
Continious SCK clock enabled make sure that the data with reset CONT bit 
is written to DSPI_PUSHR register before previous data sub-frame (with 
CONT bit set) transfer is over.
RFOF_RE Receive FIFO Overflow Request Enable. The RFOF_RE bit enables the RFOF flag in the DSPI_SR to generate 
an interrupt requests.
0 RFOF interrupt requests are disabled.
1 RFOF interrupt requests are enabled.
RFDF_RE Receive FIFO Drain Request Enable. The RFDF_RE bit enables the RFDF flag in the DSPI_SR to generate a 
request. The RFDF_DIRS bit selects between generating an interrupt request or a DMA request.
0 RFDF interrupt requests or DMA requests are disabled.
1 RFDF interrupt requests or DMA requests are enabled.
RFDF_DIRS Receive FIFO Drain DMA or Interrupt Request Select. The RFDF_DIRS bit selects between generating a DMA 
request or an interrupt request. When the RFDF flag bit in the DSPI_SR is set, and the RFDF_RE bit in the 
DSPI_RSER register is set, the RFDF_DIRS bit selects between generating an interrupt request or a DMA 
request.
0 Interrupt request is generated.
1 DMA request is generated.
Table 30-13. DSPI_RSER Field Descriptions (continued)
Field Description