In most cases, application code can be written in C or other high-level languages. However, having a basic understanding of the instruction set supported by Cortex-M processors helps developers choose the right Cortex-M processor for specific applications. The instruction set (ISA) is part of the processor architecture, and Cortex-M processors can be divided into several architectural specifications. In this issue, Joseph will take us through the most comprehensive Cortex-M processor instruction set.