An interrupt enable bit in the MCSPI_IRQENABLE
register can be set to enable each event to generate interrupt requests when the
corresponding event occurs. Status bits are automatically set by hardware logic
conditions.
When an event occurs (the single interrupt line is asserted), the processor must:
- Read the MCSPI_IRQSTATUS register to identify
which event occurred.
- Read the MCSPI_RX_0/1/2/3 register that
corresponds to the event to remove the source of an RXx_FULL event or write into
the MCSPI_TX_0/1/2/3 register that corresponds to the event to remove the source
of a TXx_EMPTY event. No action is required to remove the source of the TXx_
UNDERFLOW and RX0_OVERFLOW events.
- Set the corresponding bit of the MCSPI_IRQSTATUS
register to 1 to clear an interrupt status and then release the interrupt
line.
The interrupt status bit must always be reset after channel enabling and before events are enabled as interrupt sources.