If you can't run at the precise rate at which the target operates, then you can't do the job.

Do you have an ICE that can keep up with the 89C4x0's? It executes one instruction per clock tick. Its clock is rated to 33 MHz. Early versions operate just fine at 48 (specs say 50) MHz if you stay in the 1K block of MOVX memory. They won't run that fast in FLASH.

If you just want to run the code, you can use a simulator, if you've got one that emulates the appropriate behavior. Keil's apparently doesn't, according to their sales person who called me last week. The guy didn't even know about page modes and the variable timing for page hits and misses.

RE