Information

SPIx_SR field descriptions (continued)
Field Description
0 Transfer not complete.
1 Transfer complete.
30
TXRXS
TX and RX Status
Reflects the run status of the DSPI.
0 Transmit and receive operations are disabled (DSPI is in Stopped state).
1 Transmit and receive operations are enabled (DSPI is in Running state).
29
Reserved
This read-only field is reserved and always has the value zero.
28
EOQF
End of Queue Flag
Indicates that the last entry in a queue has been transmitted when the DSPI is in Master mode. The
EOQF bit is set when the TX FIFO entry has the EOQ bit set in the command halfword and the end of the
transfer is reached. The EOQF bit remains set until cleared by writing a 1 to it. When the EOQF bit is set,
the TXRXS bit is automatically cleared.
0 EOQ is not set in the executing command.
1 EOQ is set in the executing SPI command.
27
TFUF
Transmit FIFO Underflow Flag
Indicates an underflow condition in the TX FIFO. The transmit underflow condition is detected only for
DSPI blocks operating in Slave mode and SPI configuration. TFUF is set when the TX FIFO of a DSPI
operating in SPI Slave mode is empty and an external SPI master initiates a transfer. The TFUF bit
remains set until cleared by writing 1 to it.
0 No TX FIFO underflow.
1 TX FIFO underflow has occurred.
26
Reserved
This read-only field is reserved and always has the value zero.
25
TFFF
Transmit FIFO Fill Flag
Provides a method for the DSPI to request more entries to be added to the TX FIFO. The TFFF bit is set
while the TX FIFO is not full. The TFFF bit can be cleared by writing 1 to it or by acknowledgement from
the DMA controller to the TX FIFO full request.
0 TX FIFO is full.
1 TX FIFO is not full.
24
Reserved
This read-only field is reserved and always has the value zero.
23
Reserved
This read-only field is reserved and always has the value zero.
22
Reserved
This read-only field is reserved and always has the value zero.
21
Reserved
This read-only field is reserved and always has the value zero.
20
Reserved
This read-only field is reserved and always has the value zero.
Table continues on the next page...
Chapter 43 SPI (DSPI)
K20 Sub-Family Reference Manual, Rev. 2, Feb 2012
Freescale Semiconductor, Inc. 975