NIOS-II Cyclone II devkit timer problem

Hi all,

my problem is with Cyclone II running NIOS-II. After creating a timer in SOPC builder and implementing it to my design, I am trying to generate periodic interrupts with some desired period. However, I can never create an interrupt with frequency higher than about 130kHz - e.g. I want to create 2MHz clock on some output pin, but this is not possible, since the interrupt won't occur, although the timer's timeout period should be set to minimal value (base frequency is 85MHz, so 1-clock period of the timer should be around 11.76ns):

IOWR_ALTERA_AVALON_TIMER_PERIODL(TMR2_BASE, 10);

IOWR_ALTERA_AVALON_TIMER_PERIODH(TMR2_BASE, 0);

IOWR_ALTERA_AVALON_TIMER_CONTROL(TMR2_BASE, START_TIMER_WITH_IRQ_ONCE);

---I am using uC/OS-II operating system, but I am not sure, if it can cause this problem.

Has anybody encountered similar problem?

Any help is appreciated...