KINTERRUPT_POLARITY enumeration

The KINTERRUPT_POLARITY enumeration indicates how a device signals an interrupt request on an interrupt line.

Syntax


typedef enum _KINTERRUPT_POLARITY { 
  InterruptPolarityUnknown,
  InterruptActiveHigh,
  InterruptRisingEdge             = InterruptActiveHigh,
  InterruptActiveLow,
  InterruptFallingEdge            = InterruptActiveLow,
  InterruptActiveBoth,
  InterruptActiveBothTriggerLow   = InterruptActiveBoth,
  InterruptActiveBothTriggerHigh
} KINTERRUPT_POLARITY, *PKINTERRUPT_POLARITY;

Constants

InterruptPolarityUnknown

The interrupt polarity is unknown.

InterruptActiveHigh

Active-high interrupt. The interrupt input type is level-triggered, and an interrupt request is indicated by a high signal level on the interrupt line. The request remains active as long as the line remains high.

InterruptRisingEdge

Rising-edge-triggered interrupt. The interrupt input type is edge-triggered, and an interrupt request is indicated by a low-to-high transition on the interrupt line.

InterruptActiveLow

Active-low interrupt. The interrupt input type is level-triggered, and an interrupt request is indicated by a low signal level on the interrupt line. The request remains active as long as the line remains low.

InterruptFallingEdge

Falling-edge-triggered interrupt. The interrupt input type is edge-triggered, and an interrupt request is indicated by a high-to-low transition on the interrupt line.

InterruptActiveBoth

Active-both interrupt. The interrupt input type is edge-triggered, and an interrupt request is indicated by a low-to-high or a high-to-low transition on the interrupt line. After a low-to-high transition signals an interrupt request, the interrupt line remains high until a high-to-low transition signals the next interrupt request. Similarly, after a high-to-low transition signals an interrupt request, the interrupt line remains low until a low-to-high transition signals the next interrupt request.

InterruptActiveBothTriggerLow

Reserved for use by the operating system.

InterruptActiveBothTriggerHigh

Reserved for use by the operating system.

Remarks

A KINTERRUPT_POLARITY enumeration constant is frequently used in conjunction with a KINTERRUPT_MODE enumeration constant to describe an interrupt signal. A KINTERRUPT_MODE enumeration constant indicates whether the interrupt signal from a device is level-triggered or edge-triggered.

Requirements

Header

Wdm.h (include Wdm.h, Ntddk.h, or Ntifs.h)

See also

KINTERRUPT_MODE

 

 

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