NVME_CDW13_READ_WRITE union (nvme.h)

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Contains parameters for the NVME Read and NVME Write commands that read or write data and metadata, if applicable, to and from the NVM controller for the specified Logical Block Addresses (LBA).

This structure is used in the CDW13 parameter of the READWRITE field in the Command structure.

Syntax

typedef union {
  struct {
    struct {
      UCHAR AccessFrequency : 4;
      UCHAR AccessLatency : 2;
      UCHAR SequentialRequest : 1;
      UCHAR Incompressible : 1;
    } DSM;
    UCHAR  Reserved;
    USHORT DSPEC;
  } DUMMYSTRUCTNAME;
  ULONG  AsUlong;
} NVME_CDW13_READ_WRITE, *PNVME_CDW13_READ_WRITE;

Members

DUMMYSTRUCTNAME

DUMMYSTRUCTNAME.DSM

Indicates attributes for the dataset that the LBAs being read from or written to are associated with.

DUMMYSTRUCTNAME.DSM.AccessFrequency

An NVME_ACCESS_FREQUENCIES value that specifies the access frequency.

DUMMYSTRUCTNAME.DSM.AccessLatency

An NVME_ACCESS_LATENCIES value that specifies the access latency.

DUMMYSTRUCTNAME.DSM.SequentialRequest

Indicates whether the command is part of a sequential read or write.

For a Read operation, if this value is set to 1, this command is part of a sequential read that includes multiple Read commands. If the value is cleared to 0, then no information on sequential access is provided.

For a Write operation, if this value is set to 1, this command is part of a sequential write that includes multiple Write commands. If the value is cleared to 0, then no information on sequential access is provided.

DUMMYSTRUCTNAME.DSM.Incompressible

Indicates whether the data is not compressible for the specified logical blocks.

if this value is set to 1, then data is not compressible for the logical blocks indicated. If the value is cleared to 0, then no information on compression is provided.

DUMMYSTRUCTNAME.Reserved

DUMMYSTRUCTNAME.DSPEC

A directive specific value.

AsUlong

Requirements

Requirement Value
Minimum supported client Windows 10
Header nvme.h

See also