January 11, 2024Volume 21, issue 6 PDF The popularity of RISC-V has led many to try designing instruction sets. David Chisnall Over the past decade I've been involved in several projects that have designed either ISA (instruction set architecture) extensions or clean-slate ISAs for various kinds of processors (you'll even find my name in the acknowledgments for the RISC-V spec, right back to the first public version). When I started, I had very little idea about what makes a good ISA, and, as fa...