MPC563XM Reference Manual, Rev. 1
Freescale Semiconductor
1205
Preliminary—Subject to Change Without Notice
Each condition has a flag bit in the DSPI Status Register (DSPI_SR) and an Request Enable bit in the DSPI
DMA/Interrupt Request Select and Enable Register (DSPI_RSER). The TX FIFO Fill Flag (TFFF) and
RX FIFO Drain Flag (RFDF) generate interrupt requests or DMA requests depending on the TFFF_DIRS
and RFDF_DIRS bits in the DSPI_RSER.
26.5.10.1 End of Queue Interrupt Request
The End of Queue Request indicates that the end of a transmit queue is reached. The End of Queue Request
is generated when the EOQ bit in the executing SPI command is asserted and the EOQF_RE bit in the
DSPI_RSER is asserted.
26.5.10.2 Transmit FIFO Fill Interrupt or DMA Request
The Transmit FIFO Fill Request indicates that the TX FIFO is not full. The Transmit FIFO Fill Request is
generated when the number of entries in the TX FIFO is less than the maximum number of possible entries,
and the TFFF_RE bit in the DSPI_RSER is asserted. The TFFF_DIRS bit in the DSPI_RSER selects
whether a DMA request or an interrupt request is generated.
26.5.10.3 Transfer Complete Interrupt Request
The Transfer Complete Request indicates the end of the transfer of a serial frame. The Transfer Complete
Request is generated at the end of each frame transfer when the TCF_RE bit is set in the DSPI_RSER.
26.5.10.4 Transmit FIFO Underflow Interrupt Request
The Transmit FIFO Underflow Request indicates that an underflow condition in the TX FIFO has
occurred. The transmit underflow condition is detected only for DSPI blocks operating in slave mode and
SPI configuration. The TFUF bit is set when the TX FIFO of a DSPI operating in slave mode and SPI
configuration is empty, and a transfer is initiated from an external SPI master. If the TFUF bit is set while
the TFUF_RE bit in the DSPI_RSER is asserted, an interrupt request is generated.
26.5.10.5 Receive FIFO Drain Interrupt or DMA Request
The Receive FIFO Drain Request indicates that the RX FIFO is not empty. The Receive FIFO Drain
Request is generated when the number of entries in the RX FIFO is not zero, and the RFDF_RE bit in the
DSPI_RSER is asserted. The RFDF_DIRS bit in the DSPI_RSER selects whether a DMA request or an
interrupt request is generated.
RX FIFO Drain
RFDF
X
X
RX FIFO Overflow
RFOF
X
Table 26-41. Interrupt and DMA Request Conditions
Condition
Flag
Interrupt
DMA