Over the past few years, the notion of reusable hardware intellectual property has gone from concept to ideal to platitude. Designers have been bludgeoned to the threshold of submission by charts and graphs that clearly show that next year, their smallest design will be over 10 zillion gates, and that in order to finish in the required 11 weeks, they will have to reuse previously designed and verified IP blocks for 98.734 percent of that total.
A recent EE Times study found that, in fact, nearly half of design teams working on challenging projects reused at least some IP in their most recent design. Many engineers will nonetheless say in private that they do not believe they have ever seen a significant piece of IP reused without substantial modifications and that they would never consider not verifying a block just because it had been successfully used in a previous design. Some are outright dismissive of IP from small third-party vendors.
In this section we look at a number of strategies for making IP reusable. This being the real world, we are not looking for a way to drop a complex block into a design without modifications and with no need for system-level verification.
Rather, we are looking at strategies for getting the most practical benefit from previous work. In the case of digital IP, that means vendors' building configurability into the IP so that users can get just the configuration they need without doing anything that could break the core or take it beyond its verification constraints. We will also read arguments that configurability isn't always the right answer.
Always, verification becomes a central part of the discussion. If modification is easy but demands a complete reverification of the block, the war may be lost already. Ideally, either configurable or modifiable IP would be so arranged as to create its own verification flow as the configurations or modifications are made.
Other articles look at software IP and offer some surprising views about how supposedly target-independent C++ may in fact be eminently unportable.
And then there is analog.