Which OCTOSPI pins can be used as MOSI and MISO in single mode?

[bmn]

It is written in the STM32U575/585 reference manual (see below) that the data is sent to the external device over the SO(IO0) signal and that The data received from the external device arrives via SI(IO1).

Now, SO is known as Slave Out but here it is used as Master out, so I would expect t to be called MO

and SI is known as Slave In, and here is used as Master in, so I would expect t to be called MI.

Should I disregard the confusing names and use IO0 for MO ad IO1 for MI?

 

Thanks

[CMYL]

There is no concept of Master/Slave in OCTOSPI (not the same convention as SPI) as always the OCTOSPI contoller generates the clock.

SO here refers to Single Output not to Slave Output

SI refers also to Single Input

There is no confusing names and use IO0 for SO (single Output) ad IO1 for SI (Single Input).

BR

[CMYL · Accepted solution]

If you want to use the OCTOSPI as SPI interface, the STM32 OCTOSPI can only function as a master as generating the clock. the SO/IO0 signal will be used to output the data from STM32, then it is MOSI (master Output Salve Input). The IO1 (SI) signal will be used to receive data so it acts as MISO ...

IO0 (SO) - is the MOSI

IO1 (SI) - is the MIS0

BR

Younes