Interrupt Programming; Dma Channel Operation - Texas Instruments OMAP5912 Reference Manual

Multichannel Serial Interfaces
4.1.4

Interrupt Programming

4.1.5

DMA Channel Operation

122 Serial Interfaces
At module reset, RX_INT, TX_INT, and FERR_INT are masked.
To validate an interrupt:
If in multichannel mode, the RX and TX interrupts can be configured to occur
in a dedicated channel of the frame [1-16].
DSP_WRITE(channel_nb) = INTERRUPTS_REG(3:0) for RX_INT
-
INTERRUPTS_REG(7:4) for TX_INT
-
Unmask the interrupt:
DSP_WRITE(1) =
-
INTERRUPTS_REG(8) for RX_INT
J
INTERRUPTS_REG(9) for TX_INT
J
INTERRUPTS_REG(10) for FERR_INT
J
On interrupt occurrence:
DSP_READ =
-
STATUS_REG(0) for FERR_INT occurrence
J
STATUS_REG(2) for RX_INT occurrence
J
STATUS_REG(3) for RX character overflow
J
STATUS_REG(4) for TX_INT occurrence
J
STATUS_REG(5) for TX character underflow
J
Then, to release the interrupt signal and reset the corresponding status bits:
DSP_WRITE(1) =
-
STATUS_REG(0) for FERR_INT release
J
STATUS_REG(2) for RX_INT release
J
STATUS_REG(4) for TX_INT release
J
Both transmit and receive operations can be supported by DMA. DMA support
is enabled by control bits in the MAIN_PARAMETERS_REG:
MAIN_PARAMETERS_REG(15:14) = DMA_ENABLE(1:0)
-
TX_DMA_REQ enabled when DMA_ENABLE(0) = 1
J
TX_DMA_REQ disabled when DMA_ENABLE(0) = 0
J
RX_DMA_REQ enabled when DMA_ENABLE(1) = 1
J
RX_DMA_REQ disabled when DMA_ENABLE(1) = 0
J
SPRU760B