Confusion about the size of uncontigous flash

[G_A.]

Hello,

 

I am writing about my confusion in "STM32H742, STM32H743/753 and STM32H750 Value line advanced Arm®-based 32-bit MCUs".

 

According to reference manual;

STM32H743xI has 2 banks of 1 MByte each forming a contiguous flash memory area, so there would be no issues with a single binary spanning both banks.

STM32H743xG has 2 banks of 512 kBytes each mapped to non-contiguous addresses, there is a 512 kBytes hole between the two banks.(As far as i understand, we can create 1 or 2 project not exceeding 512 kBytes in size.)

 

But the size of  project which I created  for STM32H743xG has passed even 600 kBytes. As far as I see, there is no problem in work of firmware. How is it possible while It showing only 4 sector even in attached image? I am waiting for your response. Thanks in advance.

 

[Sarra.S]

Hello @G_A., 

Please note that it is the responsibility of the user to guarantee that these data will be accessed during code execution

knowing that ST only guarantees read/program/erase operations in the 512Kbytes declared in the reference manual  

Thank you! 

[Pavel A.]

@G_A. When you connect CubeProgrammer to your STM32H743xG  board, which flash sectors (and total flash size) does it show?

Which software have you used to program your 600K image onto the MCU?

[G_A.]

It is possible to access 16 pages(128k x 16)  using st-link utility OR CubeProgrammer . 

I used Stm32CubeIde to program my 600K image onto the MCU. Image consists of HAL library and a bare metal  structure. 

 

[Tesla DeLorean]

The parts share a common die, ST tests a subset for product stratification purposes, and costs on the test equipment.

There is some ambiguity in the dual bank devices in side-by-side vs end-to-end modes, but I think it's been generally accepted that 512KB of linear memory will be available/usable in either mode. Verify after write, and ECC, should mean these work robustly over the entire array.

[Pavel A.]

> It is possible to access 16 pages(128k x 16)  using st-link utility OR CubeProgrammer . 

This means that the ARM descriptors in the "system" memory of H743xG are same as in H743xI. So the tools believe that there are 16 continuous pages. As Sarra S. wrote, the responsibility to test the "non-warranted" pages are on the user. They may or may not work, or anything in the middle. If you just ignore these pages you are safe.