I make a 2-channel AT89S52-based frequency counter
(http://microforbetterlive.blogspot.com/2009/06/microcontroller-based-2-channel.\
html). I use timer 0 and 1 as counter. Referred to the datasheet, the timer can
count the maximum incoming frequency at 1/12 of clock frequency operation. In
fact, if we use 12 MHz clock frequency, it only can count maximum 912 kHz
incoming frequency. If we change the clock frequency to 24 MHz, it only can
count maximum 912 kHz incoming frequency too. Whereas, referred to the
datasheet, the maximum incoming frequency should up to 2 MHz (1/12 of 24 MHz).
Why the incoming maximum frequency 912 kHz?
Please, give me an explanation!
How can we build a 2 MHz AT89S52-based frequency counter?