Maximum delay can be implemented by timers

[Greital]

hi,

I'm kinda new to 8051 and have a problems with it

Q: assuming 8051 is connected to a 6Mhz crystal, what is the maximum delay that can be implemented by a single timer using mode 1 ?

what I've tried is the following:
1. finding the freq = 6/12 Mhz
2. finding the cycle of time = 1/freq
3. delay = number of counts X cycle of time ----> here I stuck how to find the number of counts ???

I'm not sure if what I'm doing is right or wrong

so please help me out with this

 

[Ian Rogers]

Using a 12Mhz crystal you will get 1uS per tick cycle....

The timer can be set to 4 modes..... 16 bit timer... 8 bit timer with pre-scaler.. 8 bit with re-load or just 8 bit timer..

8 bit with prescaler is pretty much the same as 16 bit but a bit more control..

a 16 bit timer will run for 65535 ticks or 65535 * 1uS.... That give a total 65.535mS for a complete count.If you use a 6Mhz you can double that to 131mS..

I have done a bit of an article HERE!!.. It shows interrupts using the timer!!

 

[Greital]

thanks alot for your help , really appreciate it