2.31.11 DMA_ChannelPatternMatchSetup Function
C
The prototype of this function varies based on device family. Refer to the generated header file for the actual prototype to be used.
void DMA_ChannelPatternMatchSetup ( DMA_CHANNEL channel, DMA_PATTERN_MATCH_LEN patternLen, uint16_t matchData )
void DMA_ChannelPatternMatchSetup(DMA_CHANNEL channel, uint32_t patternMatchMask, uint32_t patternMatchData)
Summary
This API is used to setup DMA pattern matching.
Description
This API is used to setup DMA pattern matching. It configures the pattern match data and pattern match length. If the pattern match length is DMA_PATTERN_MATCH_LEN_2BYTE, then matchData is 16-bit. If the pattern match length is DMA_PATTERN_MATCH_LEN_1BYTE, then the matchData is 8-bit. This API also enables pattern matching. When a pattern match occurs the transfer is aborted.
When the content of the incoming data is required in making decisions in real time, the 32-bit DMA Controller can recognize a data pattern in its internal buffer being transferred from the source to the destination locations. The pattern match capability, when enabled, allows a user-programmable data pattern to be compared against a (partial) content of DMABUF[31:0]. Upon match detection, the DMA Controller invokes its interrupt to inform the CPU to take further action
Precondition
DMA should have been initialized by calling DMA_Initialize.
Parameters
| Param | Description |
|---|---|
| channel | DMA channel |
| patternLen | Length of the pattern match data. The value can either be DMA_PATTERN_MATCH_LEN_1BYTE or DMA_PATTERN_MATCH_LEN_2BYTE |
| matchData | Pattern match data. 8-bit or 16-bit depending on the value of patternLen. |
| Param | Description |
|---|---|
| channel | DMA channel |
| patternMatchMask | The value used to mask certain bits in the incoming data |
| patternMatchData | Pattern match data. |
Returns
None
Example
DMA_ChannelPatternMatchSetup(DMA_CHANNEL_0, DMA_PATTERN_MATCH_LEN_1BYTE, 0x0d);
DMA_ChannelPatternMatchSetup(DMA_CHANNEL_0, 0x00FF, 0x0055);
Remarks
None.