FREE LESSON · Architecture & memory · 1 OF 4
Stored-Program Computer Architecture
The stored-program contract — Instructions and data share an organized machine
An ISA is the boundary software can rely on.
The instruction set architecture defines visible instructions, registers, data types, addressing, exceptions, and memory behaviour. A microarchitecture implements that contract with datapaths, control, pipelines, and caches. Different processors can run the same binary while arranging the internal work very differently.
Architecture names the promise; microarchitecture names one way to keep it.
A load instruction is a coordinated request
A load encodes an operation, destination register, and address calculation. Control decodes it; the datapath computes the address; the memory system locates the bytes; the result is extended or interpreted as specified and written to the destination. Exceptions must leave an architecturally defined state.
One instruction is a transaction across several subsystems, not a single physical action.