how to generate 100ms timer interrupt on 16f877

[rnome]

hi everybody

i need to generate a timer interrupt for 100ms in 16f877
although i search all datasheets and ccs help files and example codes, i cant find for a sensetive timer

i need this for a mobile robot's remote control unit.
i must to use a timer interrupt and in this interrupt i start a adc convertion that causes a secont interrupt (int_RA) to send converted data. sending operation takes approximately 65ms because of hardware. and for security i musnt use interrupt shorter than 65ms so i need 100ms timer int.

rnome
thanks everybody

[newguy]

This post will teach you how to do it: http://www.ccsinfo.com/forum/viewtopic.php?t=22467

[rnome]

i read that topic but it cant help me to solve my problem cuz with timer0 i can generate max 65ms timer

[PCM programmer]

Post your crystal frequency. That will help us to find a solution.

[rnome]

sorry i forget to tell about my cristall

i ll use 4mhz cristal.

thanks for reply

[newguy]

Use timer 1 - it's a 16 bit timer. With the div by 2 prescaler, it will naturally overflow (interrupt) every 2 us x 65,536 = 131.072 ms.

I'm leaving it up to you to figure out what to set timer 1 to in order to get an exact 100 ms interval.