Yes, I spoke to Atmel's engineer in California some time ago. He mentioned that they would stop supplying any 89C55 (regular once) chips.

They will ship AT89C55WD chips only.... and this happend already without notification so suppliers like Pioneer Standard ship WD series without notyfying customers.

The programming algorithm and pins for programming are completely different for WD series than regular 89C55. Do not expect any miracles if your programmer does not know how to program WD chips.


AT89C55WD has built-in watchdog and that is why it has this WD in the name.


I got in that same trouble... spent some money on about 10 chips of AT89C55 and received AT89C55WD from Pioneer Standard instead. That was though because everyting was properly packaged and market as AT89C555... by Atmel, and to my surprize inside of the rail I found chips with print AT89C55WD on the back. Now I am stuck and what's funny PIOS (Pioneer Standard) makes problems with return if the package was open. Well, how would I know what was inside if labels were okay?



Hope this helps a bit.