[QUERY] Behavior of spi slave memories w.r.t chip select signal.

viresh kumar viresh.kumar at st.com
Wed May 11 03:19:42 EDT 2011


On 05/11/2011 12:47 PM, Jamie Iles wrote:
> What SPI controller are you using?  I've seen a similar issue with the 
> Synopsys DesignWare SPI controller where the controller manages the chip 
> select itself, and once the FIFO is emptied the CS goes away, but the 
> flash chip requires it to stay high for the whole transaction.  In this 
> case the workaround is to use a GPIO as a chip select and there are 
> other controllers that do the same thing for the same reason (I think 
> that pxa2xx_spi is one of them).

I am using amba pl022 controller and using external gpio's to control
chip select signal. cs is kept low for entire message, but still i am facing
this issue.

-- 
viresh



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