Right, so, re-reading the 10F322 ds in the light of the new information fro= m AN1673, there seems to be a typo of sorts in the "high endurance flash" description table, pp 9 "TABLE 2-1" defines high endurance flash as being between 0F80h-00FFh for '320 and 1F80h-01FFh for '322, than would be 8 word= s if my interpretation of the typo is right (is it?). pp 51 "TABLE 9-1" defines flash rows as being 16 words long.=20 So the mcu has one possible row of high endurance flash at 0x1F8-0x1FF, length 8 words, but the row length is 16 ... I hope you can see how one can easily treat some wrong area of flash as high endurance with predictable results, even if it will take QUITE a while for the predictable results to manifest themselves.=20 Based on the above, my current interpretation is, that there are 8 word addresses of high endurance flash at the end of the flash memory space on '320 and '322, which can be used as normal program flash (14 bits) for the specified 10kwrites, or as 8 bit high endurance storage for data. In the latter case, the row length implies that the last 16 words of the '320 or '322 flash space be used for 8 bit high endurance data on write, which implies that the relevant ram write buffer has to be 16 words long, with actual data starting at word 8 to word 15, using LSByte only. This is = a little weird, but I can live with it. To (ds?)-mistify things even more, AN1673 pp 6 mentions that normal enhance= d arch pics have 32 byte (not word!) flash rows, while "smaller ones have 16 byte (!!) flash rows". Now, a 16 _byte_ flash row would tie in nicely with the 8 _words_ of _presumed_ high endurance flash on the '320 and '322. THEN again, if one presumes the initial typo in the high endurance flash TABLE 2-1 to be the other way around, i.e. h.e. flash from 1FF0 to 1FFF on '322, i.e. as large as on the PIC16F1509, which is a qute bigger device, then things would be really nice, with plenty of h.e. flash in nice 16 _word_ rows, with low _byte_ usable. I really need to read more on the examples provided in the forums too but I would prefer some more official ds update perhaps? Is the data h.e. flash space always disjoint from the program flash memory area? Is it always at the same address? (1F80h etc.) ? As an experienced optimist I have to say that a 128 word 'free' data storage area on a 512 word flash mcu is a nice gift to have. If it only is so... Anyway, thanks all for participating to the thread, please keep it going. -- Peter --=20 http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .