Why is a single 23-bit value not correctly written to the flash memory when I use 'HAL_FLASH_Program()'?

[ron_w]

Hello

I've managed to get the 'FLASH_EraseProgram' example program for the Nucleo-F413ZH that comes with 'STM32Cube_FW_F4_V1.25.0' working on a Nucleo-F413ZH board.

It erases sectors 2 to 15 and fills them with data - i.e. 0x78563412 that shows up repeatedly as '12 34 56 78 12 34 56 78 12 34 56 78...' in all the sectors.

However, when I try to use 'HAL_FLASH_Program()' to add a single 32 bit number to the first 4 bytes of sector 15 (starting at address 0x08160000), it does not show up correctly. For example:

// Value              Expecting              Shows up in 
// to be added        in memory              memory as
0x00000000          00 00 00 00           00 00 00 00
0x00000001          01 00 00 00           00 00 00 00 
0x00000011          11 00 00 00           10 00 00 00
0x00000111          11 01 00 00           10 00 00 00
0x00001111          11 11 00 00           10 10 00 00
0x00011111          11 11 01 00           10 10 00 00
0x00111111          11 11 11 00           10 10 10 00
0x01111111          11 11 11 01           10 10 10 00
0x11111111          11 11 11 11           10 10 10 10
34                  22 00 00 00           02 00 00 00

Considering that the padding works okay can anyone suggest what I'm doing incorrectly, please?

I'm using a Nucleo-F413ZH, MDK-ARM version 5, ARM version 5 and a ST-LINK V2 debugger.

The code (main.c and main.h) are attached.

Thanks.

Ron

[Tesla DeLorean]

You don't get multiple bites of the apple. You can write each flash line ONCE after ERASURE

[MM..1]

Or better is say you can only reprogram bits with HIGH state to zero, then after progr 0x78563412

you can only AND with this value.example

0x00011111          11 11 01 00           10 10 00 00
                    12 34 56 78 & =    10 10 00 00

[ron_w]

Thanks, @Community member​ . That makes everything clear

[ron_w]

Thanks, @MM..1​ . Good to know what is happening