Is single NOR Flash boot supported by the STM32MP15xxAD (TFBGA257 package)?

[DGree.2]

According to the wiki here: Boot from serial NOR, the pins required to boot from a serial NOR flash chip in single mode are PB6, PF8, PF9, PF10. These pins are present on the TFBGA257 package. To boot in dual mode, PH2 and PH3 are required, and these pins are *not* present on the TFBGA257 package. So from this, it seems this package supports serial NOR flash booting in single mode only.

However, CubeMX does not let me enable the QUADSPI peripheral for BOOTROM. If I try, it highlights all the choices in red and gives the error message: "Pin not available for boot step (boot ROM)".

So, is this a bug in CubeMX, or does this package not support single-chip NOR Flash booting? I'm re-designing a board to use this chip instead of a larger package, and we require serial NOR flash booting. So it'd be good to know before committing to the design.

thanks

Dan

[OlivierK]

Hello DGree.2 (Community Member)

Indeed PB6, PF8, PF9, PF10 are present on the TFBGA257 package for serial NOR flash in single mode.

In Cube Mx v6.4, the STM32mp157CADx for instance (TFBGA257 package) QSPI is available and "boot rom" box can be ticked (no red choices, only yellow since dual is not possible in this package)

 

Rgds,

Olivier

[DGree.2]

In your screenshot you have "A7NS (Linux)" checked. If you uncheck that and just check "Boot ROM" then the choices turn red. As soon as you select "A7NS (Linux)", then some choices are yellow like in your screen shot. But if you just check Boot ROM, then all choices are red or grey.

Is this just a bug or odd quirk of CubeMX?

Or does this imply I cannot boot onto NOR Flash with this package? I've poured over the relevant sections in the TRM but see nothing about limitations on serial NOR Flash booting for certain packages. Obviously there are limitations since this package lacks the pins to do dual serial NOR flash booting. So I'm wondering if this information is just missing from the TRM, or if CubeMX has a bug.

See screenshot.

[OlivierK · Accepted solution]

I wouldn't worry too much because there's the same behaviour with the BGA 448 package. So it is not a pin limitation but rather a quirk of CubeMx.

[DGree.2]

Ok, thanks for the re-assurance. Being so hard to acquire parts, we want to make sure we design for the right thing.