What is a CS32F103C8 and why do most STM32F103C8s have 128k Flash rather than the advertised 64k Flash?

[hpipon957]

Hi All

The Arduino community's Blue Pill (based on the STM32F103C8) is known as a useful but very inexpensive development board (one can order about 10 pieces for $15, including post and packaging). Also it is common knowledge that most of the STM32F103C8 chips on the boards have 128kBytes Flash (twice the size as advertised in its data sheet).

What is the explanation for chips with more Flash than expected?

Recently boards have been appearing with the CS32F103C8 on them, rather than the STM32F103C8 - is this part a clone of the original? Are they rejects of original chips or what????

Thanks

Mark

Developer uTasker project

http://www.utasker.com/stm32/BluePill.html

[Uwe Bonnes]

Only ST will know the explanation and probably will not talk about is. Others can only guess. I think it is cheaper to produce only one chip. Probably at least the upper 64 kiByte flash are not tested during production and so test time is lower and the chip can be sold cheaper.