ATMEGA 128 and TIMER3, TIMER4, INT3, INT4,

Duval JP · Joined: 22 Jun 2004 Posts: 1161 Location: France

hi everybody,

just a question, it seems these interruption are not supported yet do some guy know a solution to use them ?

thanks for your help

JP

sonero · Joined: 01 Nov 2004 Posts: 28

Hi,

This is also for Timer2 with M8/16 the same. Then you have to look at the datasheet how to set the timers and the interrupts.
This should work with a mixture of manual settings and bascom.

For example the Timer2:

Config Timer2...blabla doesn't work, you have to set TCCR2 manually (prescaler, PWM settings and so on).
On Timer2 ... works
Compare2 is unknown, you have to use "on Oc2 isr"
The same for enable/disable.
To set the value for the output compare match you have to use the register ocr2. ocr2 = blabla
One tricky thing: "Stop Timer2" works, but "Start Timer2" doesn't!!!
Just write the settings to TCCR2 again to start the timer again.
The timer runs if there is a valid prescaler written to the 4 LSB of TCCR2. If it's zero, the timer is stopped. This is supported by Bascom, but not to start it again (write the first defined prescaler again to the register).

This is only an example but like this you should get everything working like this.
Look at the datasheet for the settings of the registers and at the def-file for the names of the interrupts.

Make a simple test program to check the functions you want to use.
The compiler complains, if you use an unknown interrupt, but "Start Timer2" is accepted, even if it does nothing in fact, it simply doesn't restart the timer.
Test it in hardware, the simulator you can forget for this.

Good luck, tell us how it works.

Best regards,
Norbert