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SPI NSS configuration

love-peace2001
Associate II
Posted on July 02, 2014 at 15:16

Hello, 

Please could someone post the details to manage the SPI NSS signal? The master 

drives it ''manually'' using a GPIO bit.

 I want to use the SPI as a full-duplex master (sending and receiving data simultaneously). In the Slave side, I want to

 use the hardware slave select pin because I want to avoid using need an external interrupt to handle it. 

 I have read many posts about the NSS deficiencies in the STM32 implementation and when I have tried to make work, I didn�t success  

Thanks in advance 

#spi-slave-/cs-chip-select-nss #spi #stm32f3
2 REPLIES 2
alexis2
Associate II
Posted on March 02, 2016 at 16:38

alexis2
Associate II
Posted on March 02, 2016 at 16:41

Hi,

one year and half after you, I face the same issue. I'm trying to make communicate a Raspberry Pi [master] and many STM32F303RET6 [slaves] together trough SPI interface. In such usage (many slaves), /CS function is mandatory to avoid short circuits on bus.

I would like to trigger an RXNE IT at each transmission begining, that is to say at each falling edge of /CS from Raspberry Pi.

I used to do this with STM8.

What I experiment (with one slave only, to test) is that whether NSS pin is connected or not, an RxNE IT is triggered regarding the FIFO filling (after 5 bytes for me, the first time) but not on /CS edge.

Do somebody know if we can perform multi slave SPI communication on STM32F3x serie chips without using EXTI, as Franck said ?

Thank you in advance