The Instruction Set Architecture (ISA) of a Central Processing Unit (CPU) refers to the lowest-level interface between the programmer and the CPU, and includes the following aspects:
- Data types
- Supported operand representations
- Operations on data
- Arithmetic/other operations that can be performed on the operands
- Instruction format
- Memory organization
- Addressing modes
ISAs are also often referred to as the "Programmers Model" of a CPU
PIC32MZ, with the MIPS32® microAptiv™ MPU core implements Release 2 of the MIPS32® architecture in a 5-stage pipeline. It includes support for the microMIPS™ ISA.
PIC32MZ, with the MIPS32® M-Class M5150 MPU core implements Release 5 of the MIPS32® architecture in a 5-stage pipeline, in addition to the features supported by the microAptiv™ core ISA.
These ISAs are classified as Load/Store or Register-Register type (i.e. ALU operations act on register operands only - no memory references). On modern CPUs, this is done to decouple CPU speed from main memory speed.