.. _glossary:

Glossary
========

* **ALU**: Arithmetic/Logic Unit
* **ASIC**: Application-Specific Integrated Circuit
* **Byte**: 8-bit data item
* **CPU**: Central Processing Unit, processor
* **CSR**: Control and Status Register
* **Custom extension**: Non-Standard extension to the RISC-V base instruction set (RISC-V Instruction Set Manual, Volume I: User-Level ISA)
* **EXE**: Instruction Execute
* **FPGA**: Field Programmable Gate Array
* **FPU**: Floating Point Unit
* **Halfword**: 16-bit data item
* **Halfword aligned address**: An address is halfword aligned if it is divisible by 2
* **ID**: Instruction Decode
* **IF**: Instruction Fetch (:ref:`instruction-fetch`)
* **ISA**: Instruction Set Architecture
* **KGE**: kilo gate equivalents (NAND2)
* **LSU**: Load Store Unit (:ref:`load-store-unit`)
* **M-Mode**: Machine Mode (RISC-V Instruction Set Manual, Volume II: Privileged Architecture)
* **NMI**: Non-Maskable Interrupt
* **OBI**: Open Bus Interface
* **PC**: Program Counter
* **PMA**: Physical Memory Attribution
* **PMP**: Physical Memory Protection
* **ePMP**: Enhanced Physical Memory Protection
* **PULP platform**: Parallel Ultra Low Power Platform (<https://pulp-platform.org>)
* **RV32C**: RISC-V Compressed (C extension)
* **RV32F**: RISC-V Floating Point (F extension)
* **SIMD**: Single Instruction/Multiple Data
* **Standard extension**: Standard extension to the RISC-V base instruction set (RISC-V Instruction Set Manual, Volume I: User-Level ISA)
* **WARL**: Write Any Values, Reads Legal Values
* **WB**: Write Back of instruction results
* **WLRL**: Write/Read Only Legal Values
* **Word**: 32-bit data item
* **Word aligned address**: An address is word aligned if it is divisible by 4
* **WPRI**: Reserved Writes Preserve Values, Reads Ignore Values