Executing Program 89c51rc2h

[sean]

I am migrating an EPROM based program AMD 87c51 to the flash part 89C51RC2HBP. I downloaded and executed a test program from the Philips web site no problems. My program does not get executed on the flash part, it works OK on the AMD windowed part. I did set the status execution byte to 00.
I can read the program and the status byte back from the flash part they are correct.

Any ideas or hints, appreciate your response

Thx

[Andy Ayre]

You were able to download and execute a test program, but not your actual application?

[sean]

Correct, my application works on a windowed EPROM AMD but it does not work on the Philips flash part.

thx

[Andy Ayre]

I don't know the answer. You might have more luck posting at www.8052.com or www.philipsmcu.com where more generic mcu descussions take place.

[sean]

Just to follow up on the solution:

The problem was the execution cycle times 6-clk vs 12-clk. The default on the 89C51RC2HBP is 6-clk. I set the clock rate to 12-clk and Bingo !!
There is a newer version 12-clk default philips IC 89C51RC2xx

keep in mind that according to data sheets the programming option for the clock can only be programmed once (OTP).

Thx for the help

[Andy Ayre]

Thanks for the update.

Note that the 89C51Rx2xx devices that default to 12 clocks/cycle may be repeatedly switched between 12 clocks/cycle and 6 clocks/cycle. It is only the older 89C51Rx2Hxx that can only be programmed to 12 clocks/cycle once via a parallel programmer.