Timers

timer_0 must be defined as the system timer by default. You can change it to timer_1 by updating it in the bsp settings in NIOS SBT tool.

The prototype for alarm start is:

int alt_alarm_start

( alt_alarm* alarm,

alt_u32 nticks,

alt_u32 (*callback) (void* context),

void* context )

Think nticks is what you are looking for. You can use it to trigger a callback function after 100us systicks. One the callback is triggered, you can restart the same alarm within the callback itself.