Computer Hardware Algorithm Standard User's Guide

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1.3 Goals of the Standard
1.4 Intentional Omissions
Goals of the Standard
This section contains the goals of this standard. While it may not be possible to perfectly attain these
goals, they represent the primary concerns that should be addressed after addressing the required
elements described in the previous section.
• Easy to adhere to the standard
• Possible to verify conformance to standard
• Enable system integrators to easily migrate between TI DSPs
• Enable host tools to simplify a system integrator's tasks, including configuration, performance
modeling, standard conformance, and debugging.
• Incur little or no "overhead" for static systems
Although TI currently enjoys a leadership role in the DSP marketplace, it cannot directly control the
algorithm software base. This is especially true for relatively mature DSPs, such as the C54xx family,
where significant algorithm technology currently exists. Thus, for any specification to achieve the status of
a standard, it must represent a low hurdle for the legacy code base.
While we can all agree to a guideline that states that every algorithm must be of high quality, this type of
guideline cannot be measured or verified. This non-verification or non-measurement enables system
integrators to claim that all their algorithms are of high quality, and therefore will not place a value on the
guideline in this instance. Thus, it is important that each guideline be measurable or, in some sense,
verifiable.
While this standard does define an algorithm's APIs in a DSP-independent manner, it does not seek to
solve the DSP migration problem. For example, it does not require that algorithms be provided on both a
C54x and a C6x platform. It does not specify a multiple binary object file format to enable a single binary
to be used in both a C5x and a C6x design. Nor does it supply tools to translate code from one
architecture to another or require the use of an architecture independent language (such as C) in the
implementation of algorithms.
Wherever possible, this standard tries to anticipate the needs of the system integrator and provide rules
for the development of algorithms that allow host tools to be created that will assist the integration of these
algorithms. For example, rules related to algorithm naming conventions enable tools that automatically
resolve name conflicts and select alternate implementations as appropriate.
Maurice Wilkes once said, "There is no problem in computer programming that cannot be solved by an
added level of indirection." Frameworks are perfect examples of how indirection is used to "solve" DSP
software architecture problems; device independence is achieved by adding a level of indirection between
algorithms and physical peripherals, and algorithm interchangeability is achieved by using function
pointers.
On the other hand, Jim Gray has been quoted as saying, "There is no performance problem that cannot
be solved by eliminating a level of indirection." It is essential that the TMS320 DSP Algorithm Standard
remain true to the spirit of the DSP developer: any overhead incurred by adherence to the standard must
be minimized.
In this section, we describe those aspects of the standard that are intentionally omitted. This is not to say
that these issues are not important, but in the interest of timeliness, this version does not make any
recommendation. Future versions will address these omissions.
• Version control
• Licensing, encryption, and IP protection
• Installation and verification (i.e., digital signatures)
• Documentation and online help
Like all software, algorithms evolve over time, and therefore require version control. Moreover, as the
TMS320 DSP Algorithm Standard evolves, older algorithm components may fail to be compliant with the
latest specification. Ideally, a version numbering scheme would be specified that allowed host-based tools
to automatically detect incompatible versions of algorithm components.
12 Overview SPRU352G – June 2005 – Revised February 2007
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