Stop controller to Hanging from Genrating higher freq.

[embpic]

Hello friends
I am tried to genrate higher freq. from p89v51rd2 with 12 MHz crystal. I am using timer0 for genrating freq. and i am also updating LCD but when tried to achieve high freq. its get hang. And also have limit to genrate high freq.

This is ISR routine
{
timer0();
freq_out =~ freq_out;
}

So, help me to genrate higher freq. and update lcd.

Is there any way to interface timer555 with controller.

 

[Golden Electronics]

Controller is hanged means u enter infinite loop & reason are.
1. Due to software logic.
2. In Reading so me external pin or bit during software polling condition but corresponding
signal not recived
3. In ur case at lower frequency if it work then it may possible that at high Crystal value
ISR of timer have problem.
Please post ur code & hardware circuit dig.

 

[embpic]

i will post my s/f and h/w soon but it's working on medium freq. if i load TH0 & TL0 with near about ff and ee reap.
then it get hang.

 

[Golden Electronics]

Means it is ISR realated issue. Make very small code is ISR. Check Time Required for only ISR execution

 

[embpic]

k thanks. but i need to create higher freak. and i think there should be any way to interface 555 with controller.

 

[Golden Electronics]

why 555 interface to controller ?

 

[embpic]

to genrate higher freq. with change in PWM and most of work on burdon on timer can be reduced and timer can do another work.