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Guy Harris (talk | contribs) →Subcategories: UISA is part of instruction set architecture, and the concept, if not the name, is hardly unique to Power ISA (any CPU with a privileged mode has it, even if they don't put the privileged-mode-only instruction into a separate section of the manual). |
Guy Harris (talk | contribs) →Subcategories: Again, a "UISA" isn't distinct from the ISA as a whole. |
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* '''Macroarchitecture''': [[architectural layer]]s more abstract than microarchitecture
* '''Assembly instruction set architecture''': A smart assembler may convert an abstract [[assembly language]] common to a group of machines into slightly different [[machine language]] for different [[implementation]]s.
* '''Programmer-visible macroarchitecture''': higher-level language tools such as [[compiler]]s may define a consistent interface or contract to [[programmer]]s using them, abstracting differences between underlying
* '''[[Microcode]]''': microcode is software that translates instructions to run on a chip. It acts like a wrapper around the hardware, presenting a preferred version of the hardware's instruction set interface. This instruction translation facility gives chip designers flexible options: E.g. 1. A new improved version of the chip can use microcode to present the exact same instruction set as the old chip version, so all software targeting that instruction set will run on the new chip without needing changes. E.g. 2. Microcode can present a variety of instruction sets for the same underlying chip, allowing it to run a wider variety of software.
* '''Pin architecture''': The hardware functions that a [[microprocessor]] should provide to a hardware platform, e.g., the [[x86]] pins A20M, FERR/IGNNE or FLUSH. Also, messages that the processor should emit so that external [[CPU cache|caches]] can be invalidated (emptied). Pin architecture functions are more flexible than ISA functions because external hardware can adapt to new encodings, or change from a pin to a message. The term "architecture" fits, because the functions must be provided for compatible systems, even if the detailed method changes.
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