At first glance, there would appear to be significant benefits to DSP-core licensing; the loosely-coupled arrangement allows ASIC vendors the use of core models for end users to incorporate into their designs and tailor to their specific needs. On closer examination, however, potential problems arise for the end users.
In a recent interview, John Schanzenbach, TI's cDSP marketing manager, addressed the core licensing issue and offered TI's views regarding it's own customizable DSP (cDSP) technology and how it is applied to some common core licensing concerns.
Q: What are the most important questions a customer should ask before considering using licensed core models?
A: A critical issue is design support. Where does an end-use customer go for help? The obvious choice is the ASIC vendor from whom the core was licensed. Unfortunately, ASIC vendors typically have limited familiarity with DSP architecture, and therefore offer little technical support despite having integrated a DSP core into their ASIC library.
Q: Does that mean end-use customers must contact the designer of the DSP core?
A: That route has its roadblocks, too-the core designer is not likely to be knowledgeable about an ASIC vendor's design methodologies or fabrication process. In any of these scenarios, the customer has the ultimate burden in terms of time and money spent during the critical design cycle.
Q: Doesn't core licensing enable standardization and offer lower cost due to multi-sourcing?
A: Not really. First of all, standardization is a combined function of an installed base of software developers, customers and third parties. Currently, core licensees are design houses, chipset providers, or ASIC vendors focused on a very small customer base and are, therefore, not developing the mass market standard-product base that would result in standardization. Also, multi-sourcing is a myth in these cases; even if two ASIC vendors have the same core, the customer must still develop two designs.
Q: Are licensed cores the same from vendor to vendor?
A: Each company has its own wafer fab process, so the cores will have different characterization, electrical performance and power dissipation. Also, dramatic differences exist in manufacturing methods and environments, and this lack of consistency can result in bugs.
Q: What is TI's role in the core licensing market?
A: While TI does license its own industry-standard TMS320 DSP cores, TI cores are primarily available to customers through cDSP technology, which uses industry-standard design tools to combine DSP cores and peripherals with TI's gate array and standard cell ASIC libraries. TI's goal is to give customers the ability to manipulate features of the core model for more exact customization, and to address concerns such as cost of ownership, continuity of supply, time to market, and a long-term processor roadmap.
Q: What does cDSP offer in the way of design support that licensed core models don't?
A: Licensed-core creators often have a limited grasp of system-level issues, and licensees don't typically understand DSP. Basically, no one owns the top-to-bottom integration responsibility. Conversely, TI's cDSP program offers a methodology that takes designers through the entire design hierarchy from system to core, and cDSP's design support includes experts in both DSP and ASIC technologies.
Q: So how many cDSP designs has TI developed?
A: TI has developed more than 50 cDSP designs totalling more than 25 million devices produced.
Q: How long does it take to complete a new cDSP design?
A: It depends the complexity of the design. On average, designs take about 24 weeks from design approval to prototype.
Q:What is the minimum volume for a cDSP design?
A: cDSP designs are typically cost effective in quantities of hundreds of thousands. However, TI is also planning to meet the needs of customers needing more focused, low-volume DSP solutions using our most highly-optimized cores to create application-specific devices. These devices will be available off the shelf to customers who want to take the first step to designing in a more customized DSP solution.
Q: How much NRE is involved for a cDSP design?
A: The cost for a cDSP design is rapidly dropping. As customers want to increase cost savings and integration and speed time to market, a customizable DSP solution becomes more appropriate.