Ron LeForce

RTI Interrupt on MC9S08GB60

Discussion created by Ron LeForce on Apr 5, 2006
Latest reply on Apr 7, 2006 by Ron LeForce
Hello All.
I've been using the 'GB60 for some time now (a really nice chip, by the way). For my previous applications I've used the main timer to provide the services of "heart-beat" interrupt (background timing, etc.) This works well.
In my new application the main timer is used for other things and isn't available for the heart-beat function so I tried to use the RTI sub-system. For some reason I can't get it to interrupt.

My application uses an external 10MHz clock-oscillator but I don't use that for the RTI. This is how I init the RTI:
; set rti for internal osc and 8mSec period
lda #$51
sta srtisc ; ack and set period
lda #$11
sta srtisc ; remove ack, enable irq

According to the doc I think that should do it, but it just never interrupts.

Any thoughts?