2021-09-17 03:34 AM
We are using the STM32L4A6 in a new project. This has the QSPI peripheral that supports two 4-bit banks. The datasheet and app notes only mention using the two banks together to give an 8 bit interface, but I'm wondering, is there any way to use them for separate things?
In my case, I want to use one for a flash memory for data storage, and the other to interface to an EVE3 display.
2021-09-17 05:08 AM
No, it's a single peripheral, you can't access two chips independently. You can have two identical chips and use them both at the same time:
Dual-flash mode, where 8 bits can be sent/received simultaneously by accessing two
flash memories in parallel.
2021-09-17 05:12 AM
OK, I guess my thinking was that as there are two chip selects it should be possible to use one or the other, provided you aren't trying to access both at the same time.
I suppose we will just have to limit the speed of one by using plain SPI.
2021-09-17 05:36 AM
Put me in the maybe column.
I can use one or two devices on boards with two devices.
You'd need two instances of the QuadSPI initialization/structure
In the case I tried to use the second device independently, they shared a resource. I could see memory-map and indirect modes concurrently could be an issue.
Might want to check a DISCO board, checking solder bridges or option resistors related to NCS connectivity.
Test and/or prototype.
The OCTOSPI library I last used moved the chipset select into the command dispatch structure.