Please find our comments below.
1.) I think that VCAP is the operating voltage at the device. I found no explanation about this
voltage in the whole datasheet. Am i right?
Ans) Yes, you are correct.
2.) I understand this protection mechanism as follows:
If an autostore operation is running, no writes from a processor are possible to the SRAM-
aerea of the device STK15C88. Is this right and what is the reaction of the device in this case?
Ans) Yes it is correct. During autostore the commands will be ignored.
3.) What happens if a write operation is done in the moment when Vcc (mentioned VCAP??)
passes Vswitch and so initiates an autostore operation while the write is still running?
Ans) That write operation if completed will be reflected in the memory. If it is not completed then that operation will fail.