[Yocto] Sent wrong spi device id to spi flash

charleshuang · ‎03-11-2015

Hi

We use MX6QDL_PAD_EIM_D28 as our spi4 MOSI, but we can't ecognized SPI flash

And we use oscilloscope to measure EIM_D28,we found a strange phenomenon

As shown in below

At boot time, host will send deivce id(0X9F) to SPI,but before sending device id, EIM_D28 have a pulled LOW signals.

It will make the host sends the id becomes 0x1f.

We also have another SPI5,it will not have the phenomenon.

Both of them,we set pin control as below in dts file

MX6QDL_PAD_EIM_D28__ECSPI4_MOSI 0x170f1

MX6QDL_PAD_SD1_CMD__ECSPI5_MOSI 0x170f1

Please help to investigate this issue.

Thanks.

alejandrolozan1 · ‎03-17-2015

Hi,

Have you checked that that pin MX6QDL_PAD_EIM_D28__ECSPI4_MOS is not used in any onther node?

If it is used I recommend you to disable the module that is using it.

Best Regards,

Alejandro

charleshuang · ‎03-18-2015

Hi

We don't use this pin for the other modules

And I try to send two message ,but I found that there were still a low signals before send each message,

As shown in below

Are there any usage restrictions on the pin?

Thanks.