AnsweredAssumed Answered

ECSPI using DMA as master and slave

Question asked by peterw on Jun 10, 2015
Latest reply on Jun 12, 2015 by CarlosCasillas

Hello everyone,

 

Trying to get the ECSPI running with the DMA I get stuck.

Just a short overview. I am using two imx6q processors which should share data via the SPI (SPI5 CS1).

 

First of all I tried the example of the SDK which uses the loopback test function. This works fine.

 

Now I want to define one processor as master and the other one as slave. So far so good.

But I don’t get the desired result. Just add a screen of the logic analyzer which I use as sniffer between both processors. SPI_MASTER_SLAVE_DMA.JPG

The dummy data is received by the slave correctly. But transmitting from the slave fails. It seems that the master does not receive any data.

 

The configuration of the master:

CONREG: 0x01F4 7829 (EN, SMC, CM = 2, POST = 8, PRE = 7 CS = 1, BL = 0x1F)

CONFIGREG: 0x0000 0200

INTREG: 0x0000 0000

DMAREG: 0x0083 00A0

STATREG: 0x0000 0003

 

The configuration of the slave:

CONREG: 0x01F4 0001

CONFIGREG: 0x0000 2200

INTREG: 0x0000 0000

DMAREG: 0x0083 00A0

STATREG: 0x0000 0003

 

Thanks for any hint.

Peter

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