I'm trying to install an interrupt handler for DRV_IRQ_PFA (PF0 to 7) and DRV_IRQ_PFB (PF8 to 15). They are both, by default allied to IVG12. However, the VisualDSP++ 5.0 Device Drivers and System Services manual mentions 'secondary handlers'. As there are two interrupts within the same group, by definition, would PFA be handled by a primary handler and PFB by a secondary handler? Or is is possible to install a primary handler which can handle both interrupts therefore eliminating the need for a secondary handler?