The SST datasheet is not more than 91 pages long and much more clear than the Philips' on many aspects of the - apparently same - chip.
Of those 91, 8 pages deal with every aspect of FLASH programming, both IAP and parallel, and is absolutely crystal clear. They even didn't bother to include details on ISP itself, as those are available in form of separate appnotes, related to the bootloader (and associated toolset, including SoftICE) rather than the chip itself, IIRC.


I see nothing in "bible" nor in the datasheets preventing me to put the interrupt vectors and appropriate service routines into both parts of flash, nor that if the appropriate vectors are set and the service routines are present in the "boot flash", those interrupts won't work.

Now, Erik, some two years ago you complained on the P89V51RD2 bootloader that it does not support programming over RS485. That was the impulse why I started to look closer at these chips at all, and today I use them for most of my hobby work. And, of course, the modified bootloader supporting RS485 programming is available from my website, please, try it.

My only concern is, that this all was worked out from the suspicion - and all the evidence point into that way - that the SST and Philips parts are the same. So, until Philips admits that this is the case, or until they produce a datasheet equivalent (or hopefully better) in content to SST's, I cannot say "that's it, 100%". This is also the reason why I am using them only for hobby - I simply don't like poorly documented chips (especially if I know that better documentation IS around...)

Jan Waclawek