STM32F0 SPI--what am I missing?
Enable SPI_CR1_SSM.
The output now remains high-z since chip select is low.

Aside from clock setup and gpio, this is minimal init for SPI:

SPI2-&gt;CR1 |= SPI_CR1_SSM;
SPI2-&gt;CR1 |= SPI_CR1_SSI;
SPI2-&gt;CR1 |= SPI_CR1_MSTR | SPI_CR1_SPE;