I'm trying to simulate a simple design (written in assembler), in uVision4, that has a few memory mapped peripherals and uses P2 for GPIO. In "options for target" I set "Off-chip Ddata memory" to: Start: 0x0000 Size: 0x0100 When I run the simulator, external memory access is being done using P2, which causes problems when the value of P2 changes for GPIO. While searching the forum posts I found some mention of P2 addressing being the default for PDATA access, but found nothing about how to disable this for the simulator. Perhaps a parameter passed to S8051? Any ideas or insight would be appreciated.
you are right, the P2 bits are part of the address, but if you ignore them with a 256 bit address P2 is unaffected.
I have just never operated with that small an external RAM and thus never thought of it in that way.
so P2 IS part of the address, but not affected, so you cn ignore it if you so desire.
Even old dogs can learn new tricks
Erik