I have a project that it functions with the P89C664 to the some time, as obsolete it this, I changed for the P89V664, but with it it does not function, he is instavel, resets… somebody ja had problems similar? Some suggestion?
Yes, ja had read. Aparently the V is more sensivel and demands a more careful layout, but not yet I know accurately what to make so that it functions with stability, without resets, etc…
From V66x Migration Kees Jansen – 2006 June 1 Technical note
* Old applications with minimum decoupling might need an update for migration to the 89V66x. In general no problem are expected. A check on waveform of the Vdd of the micro is advisable.
* The ALE pin of the 89V66x must have an update with a pullup resistor (between 3k and 50kohm) in those applications where the load capacitance is larger than 30 pF during reset. Otherwise the micro might enter a test mode.