cube programmer shows 256 pages of 2K in a 256K mcu?

Forum|Forum|19 days ago
May 14, 2026
3 replies
217 views

I am using a stm32 F103RCT6 mcu. It has 256 Kb of flash memory. But when i connect it to cube programmer, it shows there are 256 sectors of 2K size which equates to 512 Kb flash.

I was even able to go to that last page and write data to it. so is the linker script generated by HAL wrong?

Best answer by AScha.3

Nothing wrong here. :)

Just you got a F103 with full flash, 512K.

Reason is: for the purpose of rationalized production only one die is produced , with 512K .

Testing the flash is "expensive" on the chip tester, so short test -> smaller flash tested -> cheaper version.

So you have a chip with 256K flash, tested and 100% working - as you ordered.

And there is more flash on the die, might work fine or not - you didnt pay for tested 512K .

So you can use it, but dont cry, if there is an error....

And linker script is ok, if 256K is used, as you ordered.

Andrew Neil

Super User

@Akshat_codes_ wrote:
I am using a stm32 F103RCT6

Where did you obtain it?

Are you sure it is genuine?

A complex system that works is invariably found to have evolved from a simple system that worked.A complex system designed from scratch never works and cannot be patched up to make it work.

A

Akshat_codes_Author

Associate II

I ordered it from LCSC. Attached below is the image

Andrew Neil

Super User

@Akshat_codes_ wrote:
I ordered it from LCSC.

You mean here: https://www.lcsc.com/ ?

Not an Authorised Distributor, so there is a risk it's fake.

Maybe this diagnostic can help you identify it ...

A complex system that works is invariably found to have evolved from a simple system that worked.A complex system designed from scratch never works and cannot be patched up to make it work.

AScha.3Answer

Super User

Nothing wrong here. :)

Just you got a F103 with full flash, 512K.

Reason is: for the purpose of rationalized production only one die is produced , with 512K .

Testing the flash is "expensive" on the chip tester, so short test -> smaller flash tested -> cheaper version.

So you have a chip with 256K flash, tested and 100% working - as you ordered.

And there is more flash on the die, might work fine or not - you didnt pay for tested 512K .

So you can use it, but dont cry, if there is an error....

And linker script is ok, if 256K is used, as you ordered.

"If you feel a post has answered your question, please click ""Accept as Solution""."

Andrew Neil

Super User

but shouldn't ~~CubeIDE~~ CubeProgrammer recognise the chip from its ID, and only report the specified memory sizes ?

A complex system that works is invariably found to have evolved from a simple system that worked.A complex system designed from scratch never works and cannot be patched up to make it work.