SPRUIM2H May 2020 – October 2023 AM2431 , AM2432 , AM2434 , AM6411 , AM6412 , AM6421 , AM6422 , AM6441 , AM6442
The TXx_EMPTY event is activated when a channel is enabled and its MCSPI_TX_0/1/2/3 register is empty (transient event). Enabling a channel automatically triggers this event, except in controller receive-only mode (see Section 12.1.4.4.3.4, Controller Receive-Only Mode). When the FIFO buffer is enabled (the MCSPI_CHCONF_0/1/2/3[27] FFEW bit is set to 1), the MCSPI_IRQSTATUS TXx_EMPTY bit is set as soon as there is enough space in the buffer to write a number of bytes defined by the MCSPI_XFERLEVEL[5-0] AEL bit field.
The MCSPI_TX_0/1/2/3 register must be loaded with data to remove the source of the interrupt; the MCSPI_IRQSTATUS TXx_EMPTY interrupt status bit must be cleared for interrupt line deassertion (if the event is enabled as the interrupt source).
When FIFO is enabled, no new TXx_EMPTY event is asserted as long as the processor has not performed the number of writes into the MCSPI_TX_0/1/2/3 register defined by the MCSPI_XFERLEVEL[5-0] AEL bit field. The processor must perform the correct number of writes.