Read from 0th index in SPI+DMA configuration

madhavaishriram — Fri, 23 Dec 2022 15:24:47 GMT

Hi All, We are using the MKE15Z256xxx7 controller for transfer and receive the data through SPI with DMA. The slave device we are using for SPI+DMA is PMOD-SF3 and trying to read and write data and it is working fine. Below is the read and write operations for slave device PMOD-SF3 WriteBuff[10u] = {0x02, 0x00, 0xff, 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06}; ReadBuff[10u] = {0x03, 0x00, 0xff, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00}; First 4 bytes are command plus address in the read and write buffer. The write operation is fine and working using SPI+DMA, but after read operation ReadBuff is containing using it. ReadBuff = {0x00, 0x00, 0x00, 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06} The first 4 bytes are empty or contains some garbase values. So the issue is to remove those first 4 bytes from the read buffer and data is read from 0th location of buffer using SPI+DMA. So is there any way to read it from 0th index after writing command + address or is there any another solution regarding this issue. - Is there anything like we can write the command and address first and we can read or write data. - Or is it possible to write the command and address from separate buffer and data from another buffer and both buffers will work at same time using DMA+SPI. - Is there any way to solve this issue using different method in SPI+DMA. Please if anyone is having any idea, please let us know how to read manipulate data in read buffer.

Re: Read from 0th index in SPI+DMA configuration

RaRo — Thu, 29 Dec 2022 17:57:53 GMT

Hello @madhavaishriram,

There is a similar question on this post: LPSPI + DMA Buffer start from 4th index - NXP Community, could you please check it?

Regards, Raul.

Kinetis MicrocontrollersのトピックRead from 0th index in SPI+DMA configuration

Read from 0th index in SPI+DMA configuration

Re: Read from 0th index in SPI+DMA configuration