NAME

AbleICR: Enable/disable ICR interrupts.

SYNOPSIS

oldMask = AbleICR( Resource, mask )
D0 A6 D0

WORD AbleICR( struct Library *, WORD );

FUNCTION

This function provides a means of enabling and disabling 8520 CIA interrupt control registers. In addition it returns the previous enable mask.

INPUTS

mask: A bit mask indicating which interrupts to be modified. If bit 7 is clear the mask indicates interrupts to be disabled. If bit 7 is set, the mask indicates interrupts to be enabled. Bit positions are identical to those in 8520 ICR.

RESULT

oldMask: The previous enable mask before the requested changes. To get the current mask without making changes, call the function with a null parameter.

EXAMPLE

Get the current mask:

mask = AbleICR(0)

Enable both timer interrupts:

AbleICR(0x83)

Disable serial port interrupt:

AbleICR(0x08)

EXCEPTIONS

Enabling the mask for a pending interrupt will cause an
immediate processor interrupt (that is if everything else is
enabled). You may want to clear the pending interrupts with
SetICR() prior to enabling them.

NOTES

The CIA resources are special in that there is more than one of them in the system. Because of this, the C language stubs in amiga.lib for the CIA resources require an extra parameter to specify which CIA resource to use. The synopsys for the amiga.lib stubs is as follows:

oldMask = AbleICR( Resource, mask ) D0 A6 D0

WORD AbleICR( struct Library *, WORD );