How did you determine that? I looked at the datasheet for the stm8s003 and wasn't able to correlate the markings to a part number.The first one seems to match stm8s003 microcontroller.
Ok, I see it now, thank you very much!I googled "phf6 qfn", got a picture of very similar chip but S103. Then googled stm8s003 datasheet, and on page 96/103 is UFQFPN20 package with marking S033 in the top row.
If you google S033 qfn you will get even better result for pictures.
by Jake Hertz
by Jake Hertz
by Jake Hertz