Topic : Ride7 problem with time

Forum : 8051

Original Post
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March 22, 2011 - 5:50pm
Guest

Hi there. I have a question about RIDE7.
Values in the column of «TIME» in the window of «Debug Output» are not correct. I use C8051F065.
In «Option/80C51/Options/Processor» chose C8051F065 device.
In «Option/80C51/Simulator» chose «Crystal frequency»=25MHz.
In simulation mode, time of the execution of one command is 1 mks, and the time of the running program is 15.778 ms in the column of «Time», although the estimated time of running program is 1.97296 ms at a clock frequency of 25MHz. After changing the frequency in «Option/80C51/Simulator» «Crystal frequency»=1MHz, time of the execution of one command is still 1mks. My program is written on the assembler MA51. What wrong?
Replies
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March 25, 2011 - 6:59am
Guest

Come on guys, please help me.
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March 25, 2011 - 9:34am
Raisonance Support Team

Hi Nayqwist,

Thanks for your question.
Our 8051 simulator is very accurate, even concerning the peripherals simulation.
However, the simulation is based on the original 8051 (circa 1980) timings. Modern 8051's have been improved, and have reduced cycle-per-instruction figures, clock multipliers etc, so the simulator timings do not precisely match the hardware figures.

We do not have plans to rewrite the 8051 simulator so that all devices work well (there are hundreds of different 8051 cores) concerning cycle timings. The best you can do is to measure using some hardware and a scope for rough timings, or to do some cycle-counting in the assembler listings (good luck on this one!)

I hope this helps,
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March 26, 2011 - 8:23pm
Guest

Hi Bruno, thanks for the detailed answer.