LPC1788 use DMA controller to transfer data from a SPI port to the CRC engine

Discussion created by lpcware Employee on Jun 15, 2016
Latest reply on Jun 15, 2016 by lpcware
Content originally posted in LPCWare by harper on Wed Aug 20 06:06:51 MST 2014
I have an external memory device connected to the SPI controller SSP1. I need to validate the content of the memory. For this purpose a CRC has been calculated and stored somewhere else (EEPROM).

To validate the memory content I want to pass all data of one SPI cycle to the CRC data register. Currently this is done by writing bytes to memory device what causes clock cycles and to copy the received bytes to the CRC data register.

To improve the performance I would like to utilize the DMA controller. The DMA is able to read the data from the SPI port. I also succeeded to pass some data from the RAM to the CRC engine.

But how can I transfer data directly from on peripheral (SPI) to another (CRC)?? The dummy bytes sent to issue clock cycles could be sent by software or another DMA channel. The only problematic task is the transfer to the CRC.