<!--
{
  "documentType" : "article",
  "framework" : "SCSIControllerDriverKit",
  "identifier" : "/documentation/SCSIControllerDriverKit/SCSIControllerDriverKit-macros",
  "metadataVersion" : "0.1.0",
  "role" : "collectionGroup",
  "title" : "Macros"
}
-->

# Macros

## Topics

### Macros

[`#define kIOHierarchicalLogicalUnitSupportKey`](/documentation/SCSIControllerDriverKit/kIOHierarchicalLogicalUnitSupportKey)

[`#define kIOMinimumHBADataAlignmentMaskKey`](/documentation/SCSIControllerDriverKit/kIOMinimumHBADataAlignmentMaskKey)

[`#define kIOServicePowerCapabilityPause`](/documentation/SCSIControllerDriverKit/kIOServicePowerCapabilityPause)

A PCIe-specific power state for halting transactions while reallocating resources.

[`#define kMaxSenseBufferSize`](/documentation/SCSIControllerDriverKit/kMaxSenseBufferSize)

The maximum size of the SCSI sense data buffer in a response.


---

Copyright &copy; 2026 Apple Inc. All rights reserved. | [Terms of Use](https://www.apple.com/legal/internet-services/terms/site.html) | [Privacy Policy](https://www.apple.com/privacy/privacy-policy)