From my reading of the data sheet I understand that the chip does not even permit reading after the error counter gets to max count. All that is for certain is that once the error counter reaches maximum (eight total errors I believe) it is necessary to use the proper PSC in order to once again access the chip.

The reason it has to work like this is that the chip has to stop responding so that a hacker has way no determining if further attempts to access the chip are successful. Otherwise the hacker could continue trying till he got it. After all, 65536 possible PSC codes are not that many and a automated hacking scheme would not take too long to cycle through all of the possible choices. This chip is designed to try to prevent this discovery process.

Michael Karas