AnsweredAssumed Answered

NSS stays low after disabling SPI

Question asked by p.denis.001 on Dec 9, 2015
MCU: stm32f103rf
SPI: SPI1 without remap, MSTR = 1
SPI1 NSS pin PA4 configured as AF push-pull
PA4 remains low independent of SPI state (SPE, SSOE). When PA4 configured as GPIO it is working fine.
When running the same code with remaped SPI1 (also remap to SWD), NSS pin(PA15) goes high after it's configuration and enabling SPI1 clock (in any order).
Then it goes low after {SSOE = 1;  SPE =1}. Then it goes high after SPE = 0.

Outcomes