Original: E.g. the C , C++ , or Java standards define different Programmer Visible Macroarchitecture - although in practice the C microarchitecture for a particular computer includes UISA ( Microcode Instruction Set Architecture ) - a family of machines with different hardware level microarchitectures may share a common microcode architecture , and hence a UISA .
Simplified: UISA ( Microcode Instruction Set Architecture ) : A family of machines with different hardware level microarchitectures may share a common microcode architecture , and hence called a UISA .