stm32 spi half-duplex transmit into receive mode

[Staly.1]

the target type is stm32f072, firstly the master transmit data success, slave receive data ok;

should i need to disable spi ,enable BIDIOE in slave. but the slave can't transmit data, how to solve it?

[prain]

what is your SPI slave? bidirectional mode is not supported by all SPI devices. It is a request / response protocol. Normal SPI use simultaneous data transfer on miso and mosi lines.

[TDK]

The master always drives the clock. Slave can only wait for the clock and send out data.

The reference manual has a section on how to do this. You're not trying to have the chip be a master, then turn into a slave, are you? That's not how it should work.

[Staly.1]

my spi slave is stm32f031, the connection is master MOSI to slave MISO

[prain]

be aware that slave can not initiate a transfer. bus management and clock generation​ can be done only from master side. If you want to send data from slave to master, the master should send junk data to initiate transfer

[Jseyn.1]

thank you for your reply, i 'ill try to send junk data in the master side