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Table 46-102. Interrupt and DMA request conditions
Condition Flag Interrupt DMA
End of Queue (EOQ) EOQF Yes -
TX FIFO Fill TFFF Yes Yes
Transfer Complete TCF Yes -
TX FIFO Underflow TFUF Yes -
RX FIFO Drain RFDF Yes Yes
RX FIFO Overflow RFOF Yes -
Each condition has a flag bit in the module Status Register (SR) and a Request Enable bit
in the DMA/Interrupt Request Select and Enable Register (RSER). Certain flags (as
shown in above table) generate interrupt requests or DMA requests depending on
configuration of RSER register.
The module also provides a global interrupt request line, which is asserted when any of
individual interrupt requests lines is asserted.
46.4.7.1 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 set
and the EOQF_RE bit in the RSER is set.
NOTE
This interrupt request is generated when the last bit of the SPI
frame with EOQ bit set is transmitted.
46.4.7.2 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 RSER is set. The
TFFF_DIRS bit in the RSER selects whether a DMA request or an interrupt request is
generated.
NOTE
TFFF flag clears automatically when DMA is used to fill TX
FIFO.
Functional description
K20 Sub-Family Reference Manual, Rev. 1.1, Dec 2012
1224
Preliminary
Freescale Semiconductor, Inc.
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