Boot configuration for STM32G071

[AShel.1]

For STM32G071 controller, I see difference in information provided in Ref manual (RM0444 Rev4) and STM32 microcontroller system memory boot mode applicate note(AN2606 Rev44).

1. In Ref manual on Pg 60 section 2.5 it is mentioned that for selecting boot from system memory we’ve 2 options.
2. Option Byte from Ref Manual, pg no 73 section 3.4.1 says that all nBOOT0, nBOOT1, nBOOT_SEL bits are 1
3. so any of the option to select system memory boot will not work unless I change the option byte value in user application or using tools like STCubeProgrammer or DFuseDemo
4. In Application note(AN2606), on pg no 206 section 40.1 it is mentioned to refer pattern 11 from table 2 for STM32G07 controllers.
5. Pattern 11 from table 2 pg no 24 section 4.1, 2nd option does not check nBOOT0 bit in option byte. So this option does not require any change in option byte as rest fields nBoot1 and nBOOT0_SEL bits are already set to 1 as in default value.

My questions:

1. Is there error in documentation wherein this difference is just an error?
2. If there is error in documentation, can I get correct document?
3. If Application note(AN2606) is correct then can I enable boot from system memory? 

Thanks,

 

[Imen.D]

Hello @AShel.1​ ,

Thanks for pointing out this difference. I am checking it and I will come back to you with update.

Imen

[Imen.D]

Hi @AShel.1​ ,

Please refer to the latest revision of RM0444 (Rev 5) and  AN2606 (Rev 46) which are available in the ST web site and contains update and correction.

 

All your feedback are welcome.

Imen

[AShel.1]

Thanks for taking prompt action, so with these options one cannot enter into system memory without modifying option bytes.

as default values in option byte does not fit into any of the above config combinations

I wanted to just control BOOT pin to enter into system memory and leave option bytes as default setting. please let me know if I can still achieve it some other way.

thanks,

[Imen.D]

The pattern is built depending on the boot table of the STM32. You can check on the Table 8. Boot modes (page 66) on the RM0444: It seems the scenario needed is not possible.

Imen

[AShel.1]

Hello,

I've another observation, may be something wrong in board.

host controller is sTM32H573 which will update firmware of slave controllers interfaced on SPI one is sTM32G071 and is STM32G474, I'm using nucleo-g474re board

for sTM32g474 controller system memory boot configuration as per ref manual RM0440 Rev 4 pg no 89,

nBOOT1, nSWBOOT0 bits in option byte should be set to '1' and BOOT0 pin should be pulled high.

in reference manual RM0440 Rev 4 pg no 109 it is mentioned that default value of nSWBOOT0 bit is set to '1'. so no need to modify option byte to enable system memory boot.

I've tried reading option bytes of nucleo board(board is new) using STM32CubeProgrammer and it reads nSWBOOT0 as '0' if this is the case then again I'll have to modify option bytes to enable system memory boot. please check and provide your inputs.