implementing read operation using M-SPI between BCM7358 and SPI NOR

Question

SPI subsystem sitting between BCM7358 and SPI NOR flash use B-SPI module to perfrom read operation and M-SPI module to perfrom the write operation....If I have to perfrom read operation from M-SPI as an substitute of B-SPI...then how can I proceed....any suggestion are welcomed

Answer 1

You will need to find the programming information for the master spi interface, or else find a driver module compatible with your OS or example code you can crib from.

Assuming you want to do the access while your system is running rather than in order to boot from the SPI, what you want to do seems pretty reasonable so the chances of finding useful information are good.

If you are trying to do this to boot, you may need to boot a small bootloader from something else which can "manually" load an image with the master spi and then jump into it. Or else see if the chip has a mode pin combination or the like to boot from the master spi interface instead.

Essentially, if you made your own board and sourced chips without data sheets, you are in trouble unless you can find something else using a similar enough chip to crib from. Similarly if you are hacking a modification to a product without any source code. But if you bought an eval board or module, presumably you have access to some documentation or example code for the board, even if not for the chip.