Miles Sound System SDK 7.2a

DDK Digital Function: IRQ_validate

Discussion

Input:

IRQ variable in VDI_HDR = interrupt #

Output:

Carry set if IRQ valid
All registers preserved

Purpose:

Tests for spurious or invalid IRQ signals

Notes:

On many IBM AT-compatible systems, spurious IRQ 7 signals frequently occur. This function should be called at the beginning of the sound ISR to reject these false IRQs.

If IRQ_validate returns with the carry flag clear, the ISR should IRET immediately, without processing or acknowledging the interrupt.

Does not require valid DS register.

Group: DDK Support Routines for Digital Sound Drivers
Related Structures: VDI_HDR