The process of writing microcodes (low-level codes) is known as Microprogramming. The written microcodes are generally used in microprograms. Usually, the microprogramming is carried out for the microprocessors. In microprogramming, the output signals are normally stored in a ROM (Read Only Memory).
Applications of Microprogramming
There are various applications of microprogramming. One of the benefits of microprogramming is that, while doing microprogramming the realization of the computer is achieved. It can be used to support monitoring detection and isolation. Sometimes the repair of system error is also carried out by the microprogramming. One of the standard techniques used in microprogramming is Emulation.Emulation technique in Microprogramming
In Emulation technique, the originally written program is executed for another program. The main function of such program or technique is to provide a systematic operation for control unit implementation. The important application of microprogramming or microprogram is that it is often used in the field of operating system supports.The various types of instruction used are arithmetic instructions, logical instructions, I/O instructions and so on. Also, many instructions are required for moving data & information to and from system main memory. Similarly, the same instructions are also used for moving data to and from processor registers. Other types of instruction used are the program control instructions which is generally set to check status conditions.
What is Instruction Pipelining?
The instruction pipelining is one of the standard feature of the Reduced Instruction Set Computer (RISC) processors ( they are the fetched computer which uses lesser instruction with a simple construct) where multiple instructions are overlapped in execution. Use of instruction pipelining increases the performance and speed of the Central Processing Unit (CPU). It is also known as instruction processing where the operation is carried out in two phases.The first phase is the fetched instruction cycle and the second one is the execution instruction cycle.
The various elements used in the instruction are fetched instruction, execute the instruction, decode the instruction, write operand, fetch operand, calculate operand, etc.
Both the phases are the independent stages where processing of instructions is carried out. The first stage is fetched cycle where the instruction is fetched and buffers it for the execution. At first, the instruction is sent to the fetch instruction cycle and after fetching the instruction; the fetched instruction is passed to the execution cycle. The fetch cycle causes an instruction to be fetched from the main memory.
When the first phase uses the unused memory, the second stage is carried out to execute the fetched instruction. The same process repeats again and again until all the instructions are fetched & executed. The current fetched instruction helps in buffering the next instruction. This type of processing is also termed as instruction prefetch.
We should be aware between instruction pipelining and RISC pipelining. In RISC (Reduced Instruction Set Computer) pipelining, many sub-operations are carried out and executed in one clock cycle. All the fetched & executed instructions have register to register operations in the RISC pipelining. Therefore, we can say that the RISC pipelining is the process for implementing the instruction pipelining in a small number of sub-phases.