STM32L4R9 SPI bootloader. Strange behaviour after executing global mass erase command

[MSipo]

I'm programming an STM32L4R9 through SPI according to the AN4286 application note.

The problem I have is that after a global mass erase command (0x44) it won't let me execute the read memory (0x11) or the write memory (0x31), even if I wait several seconds after the global mass erase.

To solve this, I must after global mass erase restart the MCU into bootloader mode again, then read memory and write memory commands work.

I have previously used my bootloader client for the STM32F429 and it had not this problem.

Anybody knows why it behaves like this?

[Imen.D]

Hello @MSipo,

Have a look to the errata sheet related to the STM32L4R9 devices, to check if you have the same conditions as described in the doc.

It May be related to the section: 2.2.13 Bootloader not functional on 1‑Mbyte devices.

Imen

[MSipo]

The bootloader version is 9.2.

At least I can make it work by restarting the bootloader after a global mass erase before I run any write memory command. 😀