Choosing Chip / Slave Select (CS / SS) pins for an R3 SPI shield

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Anonymous
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I have a CY8CKIT-042BLE kit and decided to develop a little application with an Arduino R3 shield which uses SPI communication. The shield has hardwired the CS/SS pin as Arduino pin 7, which translates to P1.0.

   

Now in PSoC Creator I went to assign my pins and was surprised to see that P1.0 was not available for me to use as a SS.

   

I am now most curious to learn why is that.

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1 Solution
Bob_Marlowe
Level 10
Level 10
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PSoC 4 has limited routing capabilities for SCB blocks.

   

Workarounds: use USB based SPI Master (v2.50)

   

or control ss pin yourself (that's more reliable) by setting the pin accordingly at begin and end of a transaction.

   

 

   

Bob

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3 Replies
Bob_Marlowe
Level 10
Level 10
First like given 50 questions asked 10 questions asked

PSoC 4 has limited routing capabilities for SCB blocks.

   

Workarounds: use USB based SPI Master (v2.50)

   

or control ss pin yourself (that's more reliable) by setting the pin accordingly at begin and end of a transaction.

   

 

   

Bob

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Anonymous
Not applicable

Thanks Bob. Yes controlling the SS pin yourself makes better sense. I did not realise you could set number of SS to zero in the SCB SPI block.

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Bob_Marlowe
Level 10
Level 10
First like given 50 questions asked 10 questions asked

I didn't know either 😉 I usually picked my own pin for that purpose.

   

 

   

Bob

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