Hi all,
We're struggling with a problem with a custom RT1062 board. We have had it working with an ISSI external QSPI flash chip. We've now put an Infineon chip on and it's not working. Part of the issue is that someone who originally got the board working wth the ISSI chip has gone, so he might have been able to answer this.
From doing a load of reading it looks like this *might* be the situation, I'm hoping someone can advise:
1. There is an OTP 32-bit value you have to program to tell the processor's ROM bootloader what kind of external flash is attached ot the chip. If you program this for one type of chip and another is fitted, unless you change the SPI chip and put on the one you have programmed the processor to expect, the board is unusable?
2. It looks like as long as the SPI flash device supports JESD216x then if you program the 32-bit OTP correctly, it should work.
3. Is it the case that dependent on the 32-bit OTP value, the 1062 ROM code will select which command set to use to talk to the SPI flash chip and therefore know which are the correct commands to, for example, switch from single SPI to Quad SPI?
3. This is likely outside of the scope of this forum, but I'll as just in case. We have put the Infineon S25FL256 device on our board. Should that work? It says it has JESD216B serial flash discoverable parameters.
4. If the Infineon chip should work, does that mean that as long as our OTP value is set correctly, the boot ROM will communicate correctly with it? Or is it more complicated than that?
If that *is* the case, is that something to do with bits 11:08 in the 32-bit value? I don't understand what it means about things like set bit 6 in Status register 1. Status register of what? The flash chip? The processor itself?
My assumption would be, as these flash chips are so ephemeral, that it must be the case that you can't be too tied down to a specific chip and it must be possible to be able to swap and change devices.
Many thanks.
