RM0455: Where is OCTOSPIM clock enable bit in STM32H7A/B ?

[Andreas Bolsch]

RM0455 rev. 3 doesn't mention the OCTOSPI*M* clock enable at all. As OCTOSPIM is on AHB, this bit should be in one of RCC_AHB1ENR, ..., RCC_AHB4ENR registers.

On the other hand, there is a mysterious IOMNGREN bit in RCC_AHB3ENR, and this IOMNGR is not mentionend anywhere else.

Apparently IOMNGREN is in fact OCTOSPIM clock enable, as after setting it OCTOSPIM registers become available at 0x5200B40X as expected.

The very same applies to IOMNGRRST in RCC_AHB3RSTR as well.

[Amel NASRI · Accepted solution]

Good catch @Andreas Bolsch​ ! Indeed IOMNGR* bits are the ones that need to be used with OCTOSPIM.

The RM0455 will be updated in order to align RCC registers with related peripherals.

-Thanks.

-Amel

[Amel NASRI]

Hello,

Please note that RM0455 was update and currently OCTOSPIM* bits are described in RCC registers.

-Amel