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[LS1043ARDB] DSPI CS pin behavior

Question asked by Randy Wang on Jan 11, 2019
Latest reply on Feb 10, 2019 by Randy Wang

Dear All,

I added spi device TPM via ls1043ardb dspi.

TPM driver is OK and modprobe well.

bus can't get the respose.

and I capture the spi timing as following:

nxp_spi

IN: MISO, OUT:MOSI,

And I compared another board, raspberry pi3, which the TPM works well on it, 

and captured the spi timing as following:

 rasp_spi

The difference is the spi chip select signal.

on the raspberry pi3, the CS is enabled all the way for entire transaction.

but on the ls1043ardb, the CS is disabled after the first 4 bytes.(Red circle mark)

does it meaning the CS should not be disabled right after the first 4 bytes?

if yes, how can I configure the SPI CS behavior?

 

Thanks.

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