UART DMA
2-46 ADSP-21368 SHARC Processor Hardware Reference
When performing DMA using the UART module, receive interrupts are
generated when:
• The receive word block is complete/the DMA is complete.
• A receive overrun error is detected.
• A receive parity error is detected.
• A receive framing error is detected.
• An address detect interrupt (for 9 bit mode) is detected.
The transmit interrupt is generated when the transmit word block is com-
plete/the DMA is complete.
To start a chain pointer DMA use the following steps.
1. Initialize the chain pointer register with the address of the DMA
descriptor table. Set the
PCI bit if an interrupt is needed at the end
of each DMA block.
2. Set up the appropriate control register to enable the UART trans-
mitter and receiver, chain pointer, and DMA. Once chain pointer
DMA is enabled, the DMA engine fetches the index, modify,
count, and chain pointer values from the memory address specified
in the chain pointer register. Once the DMA descriptors are
fetched, normal DMA starts. This process is continued until the
chain pointer register contains all zeros.
To Next Page
Loading...
Need help?
General
