Articles by Cliff Maier, PhD
If you have a logical function that needs to be implemented, how do you break that down into the logic gates that correspond to “standard cells” in order to actually implement the design with transistors? There are certainly automated ways to do this. For example, nearly everyone (apart from...
Tick tock.
To a CPU designer, a clock is a signal that is used to synchronize the behavior of different circuits. As discussed in earlier articles in this series, a CPU consists of two types of logic: synchronous logic and combinatorial logic. The synchronous logic consists of circuits that...
In Part 4 I explained that when it comes to memory, you essentially have to trade off capacity vs. speed. If you want a large pool of available memory, it will tend to be slow compared to a small pool of memory. I also explained that you can take advantage of this trade-off by using multiple...
Introduction
I’ve received a request to talk about caches, which is a topic near and dear to my heart. In fact, my Ph.D. dissertation was a rather lengthy book on the topic. The last I checked, my old research group was still hosting an html version of my dissertation here.
I’ll get to...
Power efficiency has increasingly become an important issue in CPU design. Performing calculations is not free - you have to supply power in order to enable the CPU to move electrical charge carriers around in such a manner as to perform computations. There are many techniques that CPU...
In Part 1, we discussed how the architect decides how the processor behaves. The next step is for the logic designer to decide how to produce that behavior. When I use the term “logic design,” I use it the way it was used at the various companies I worked at (AMD, Sun, Exponential Technology)...
”Architecture” may mean different things at different companies, but at the companies I worked at it had a fairly consistent meaning. “Architecture” should be distinguished from “instruction set architecture” (ISA). The vast majority of the time, when we are designing a CPU, the instruction...