Project 1545 - INCITS 401, Information technology - SCSI
Multimedia Command Set - 4 (MMC-4)
This standard defines a set of SCSI command descriptor blocks that are
useful in accessing and
controlling devices with a peripheral device type set to 5.
This command set is transport independent and may be implemented across
a wide variety of
environments for which a SCSI transport protocol has been
defined. To date, these include Parallel
SCSI, ATA/ATAPI, Serial ATA, Universal Serial Bus (USB versions 1.1 and
2.0), and High
Performance Serial Bus (IEEE 1394, 1394A, and 1394B).
The command set described has been selected for correct operation when
the physical interface is
ATA with the ATAPI command protocol. Although some commands are
also described in the SPC-3
the descriptions are also in this standard for the purpose of profiling
mandatory and optional
command features as applied to multi-media devices.
The objective of this command set is to provide for the following:
- A definition of the command formats and functions independent of
delivery, protocol/signaling or transport mechanism.
Architectural constraints regarding command functions, over the various
transports, are addressed in the document specific to the physical
transport.
- Standardized access to common features of devices employed
in multimedia applications.
- System software/firmware independence across device classes and
physical interfaces.
- Provision is made for the addition of special features and
functions through the use of vendor-specific options.
- To provide compatibility such that properly conforming devices
may inter-operate with subsequent devices.