The µC STM32F051Kx has only one SPI and of course only one CS (chip select). It is possiblie to use another and configure it as CS?

[Uwe Bonnes]

Of course you can bitbang other pins as CS.

[SAbis]

thanks very much.

do you have any idea on using the UART interface to upload Firmware? We are using only this interface to communicate between our controller and to reduce the Pin-number and an extra connector for SWD (serial wired debu), I am planning directly to use the same communication interface (RS485) to upload my firmware. is this possible? if yes how could i realise it in Hardware?

Thanks