This is a general question, i'm used to using PIC's, and AVR's and not really 8051's. Do most people set the interrupts to another bank with 'using' and leave the rest of the code with the default. Just after some experienced users guidelines. Also we have an 8051 ASIC with 128k code and ram, 2 SPI's etc. I was looking at defining the resources so the compiler knows about this stuff. I'm a little confused about how the compiler would treat it. ie the 128k data is internal to the ASIC but does the compiler still have to treat it as external? thanks David
David Pleydell: "the 128k data is internal to the ASIC but does the compiler still have to treat it as external?" Yes, it does. All the Compiler "knows" about is the 8051 "core" - and, as far at that's concerned, the 128K is "external" - it still has to use MOVX etc instructions to access it. I'm using the Triscend E5 parts, which have an 8032 "core" plus programmable logic plus RAM on a single chip, so I've been through all this! http://www.triscend.com/products/e5.htm The option on uVision, "Use On-Chip XRAM" is a little misleading, as it doesn't actually do anything to control whether on- or off-chip RAM is used (that's done by Triscend's utilities) - it's just a quick way to tell the Linker how much XRAM it's got to play with. Robert Wey: "my guess would be that the 128K of internal RAM is likely accesses as xdata" Or PDATA?