This article is a primer into the basics of RISC-V. The open architecture philosophy is exposed, along with a technical description of the modular ISA, and some commercial RISC-V microprocessor implementations.
The RISC-V open instruction set architecture is a popular alternative to proprietary architectures available today, such as those by ARM. Since its birth, RISC-V has steadily gained academic and commercial popularity.
Understanding RISC vs CISC
RISC is a computer architecture philosophy proposed in the 1980s as an alternative to the commercial architectures offered at the time by Intel, Motorola, and pretty much everyone else. Originally dubbed as “Complex Instruction Set Computer,” or CISC, this architecture relied on dense instruction sets to implement a wide variety of operations thought to be useful and necessary. However, many research teams including IBM and UC Berkeley found that compilers usually ended up using a very small subset of these complex instruction sets. This, and other findings, led to questioning the need for a larger instruction set, focusing on simplicity as a means to improve efficiency.