I'd like to remove SPI_CS pin while we are using SD card externally

[sangyun Kim]

for the schematic to connect between nRF52840 and external SD memory card, we are using miso, mosi, clk, detect, CS.

is it possible to remove CS pin to reduce pin connection for the nRF master mode?

I could find the spec as below from nRF52840_PS_v1.7.pdf

...

[Jared]

Hi,

Doesn't the SD card require the CS signal? SPIM 0-2 doesn't have HW control of the CS signal so it's usually controlled externally of the peripheral ( the SPIM driver sets it here), It should be ok for the Master to not use it but the slave might not work if the CS isn't asserted first,

regards

Jared