I might approach the problem by using the T2 on an 8052 as a free running interrupt generator, and one of the other timers to count pulses of the frequency output. Every T2 interrupt, read the number of pulses accumulated, and reset the pulse counter.

The number of pulses recorded per T2 interrupt will then be proportional to the frequency you are measuring.

Hope this helps.

I don't consider myself an 8052 expert, because I'm just tackling my first project with it. But if you want to see how to set up the reset/interrupt vectors, and make T2 operate as a stand alone interrupt generator, I can send you some source code. Email me direct if you want this.

Regards,

Dave Fletcher

dave_fletcher@bigfoot.com