Smáforritunar

Smáforritunar is an Icelandic term that translates to "microprogramming." It refers to a technique in computer architecture where the control unit of a central processing unit (CPU) is designed using a small, specialized program called firmware. This firmware, stored in read-only memory (ROM) or programmable read-only memory (PROM), contains sequences of microinstructions that dictate the operation of the CPU for each machine instruction.

Instead of directly implementing complex instruction sets with hardwired logic, microprogramming allows for a more flexible and simpler control unit design. Each machine instruction is broken down into a series of microinstructions. When the CPU fetches a machine instruction, it then fetches and executes the corresponding microprogram sequence, which activates specific data paths and functional units within the CPU to perform the desired operation.

The primary advantage of microprogramming is its flexibility. Changes or additions to the instruction set can be made by updating the microprogram without altering the physical hardware. This also facilitates the implementation of complex instruction sets and aids in CPU design and debugging. However, microprogrammed CPUs can sometimes be slower than those with hardwired control units due to the overhead of fetching and executing microinstructions. The concept of microprogramming was particularly prevalent in early computer designs but remains a fundamental aspect of understanding CPU control mechanisms.