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T4 - Async updates - Hack for high memory...
If a buffer is up in the high memory, that is either in the area marked DMARAM or created by malloc and you try to do a SPI transfer using DMA, the code detects the addresses >= 0x20200000 and then calls the system functions to either flush the cache or delete the cache on the read...main
Kurt Eckhardt
5 years ago
1 changed files with 2 additions and 0 deletions
+ 2
- 0
SPI.cpp
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| if (buf) { | if (buf) { | ||||
| _dmaTX->sourceBuffer((uint8_t*)write_data, count); | _dmaTX->sourceBuffer((uint8_t*)write_data, count); | ||||
| _dmaTX->TCD->SLAST = 0; // Finish with it pointing to next location | _dmaTX->TCD->SLAST = 0; // Finish with it pointing to next location | ||||
| if ((uint32_t)write_data >= 0x20200000u) arm_dcache_flush(write_data, count); | |||||
| } else { | } else { | ||||
| _dmaTX->source((uint8_t&)_transferWriteFill); // maybe have setable value | _dmaTX->source((uint8_t&)_transferWriteFill); // maybe have setable value | ||||
| DMAChanneltransferCount(_dmaTX, count); | DMAChanneltransferCount(_dmaTX, count); | ||||
| _dmaRX->TCD->ATTR_SRC = 0; //Make sure set for 8 bit mode... | _dmaRX->TCD->ATTR_SRC = 0; //Make sure set for 8 bit mode... | ||||
| _dmaRX->destinationBuffer((uint8_t*)retbuf, count); | _dmaRX->destinationBuffer((uint8_t*)retbuf, count); | ||||
| _dmaRX->TCD->DLASTSGA = 0; // At end point after our bufffer | _dmaRX->TCD->DLASTSGA = 0; // At end point after our bufffer | ||||
| if ((uint32_t)retbuf >= 0x20200000u) arm_dcache_delete(retbuf, count); | |||||
| } else { | } else { | ||||
| // Write only mode | // Write only mode | ||||
| _dmaRX->TCD->ATTR_SRC = 0; //Make sure set for 8 bit mode... | _dmaRX->TCD->ATTR_SRC = 0; //Make sure set for 8 bit mode... |
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