SPI Slave and csn pin enable by software

[MeliodasD]

Hi there,

On my custom hardware, I am running out of I/O pins and I want to leave the SPI slave active like if csn_pin were enabled/connected to an SPI master, is it possible enable CSN PIN by software on the SPI slave? to simulate an SPI master is enabling it?

regards

[Susheel Nuguru]

Do you mean not to use any GPIO and leave the CSN pin active low . No, You cannot do that, you need to connect the CSN to some gpio for proper functioning of the peripheral. Also the semaphore feature is completely based on the CSN pin, so if you are not driving the CSN pin externally, then you could have write conflict issues in RAM between SPIS and CPU where TXD/RXD pointers are pointing to.

[MeliodasD]

Thanks for the reply, now it is clear for me :)