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ecSPI Problem sending number of bytes which is not dividable by 4

Question asked by peterw on Mar 26, 2015
Latest reply on Apr 12, 2015 by peterw

I’m a bit confused what’s going on with the SPI on the i.MX6. Using the SPI driver from the Freescale SDK I tried to send 10 bytes from the master to the slave.

I just build up a test scenario where the master sends the 10 bytes and with a logic analyzer the MOSI is checked.

Sending data is 0xA0 to 0xA9 and the result in the logic analyzer is:

0xA1 0xA0 0xA7 0xA6 0xA5 0xA4 0x00 0x00 0xA9 0xA8

So in that case the 0xA3 0xA2 at the beginning are missing.

As I send a number of bytes which is dividable by 4, there is no problem.

I can expect that if the number of bytes is not dividable by 4 the last bytes are filled up. But as I can see there are 2 byes missing in the first 4 byte block.

It’s not as easy to explain the problem, so if there are any questions about this scenario….

 

Thanks for any hints.

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