An embedded system is built using a series of building blocks. Let’s take a closer look at them.
- Input Devices
- Output Devices
- Central Processing Unit
- Communication Interfaces
- Memory (ROM and RAM)
- Application Specific Circuit
RISC and CISC
RISC – Reduced Instruction Set Architecture
By adopting an instruction set consists of a few fundamental steps for loading, evaluating, and storing operations, the primary goal of this is to make hardware simpler. A store command will store the data in the same way as a load command loads it.
CISC – Complex Instruction Set Architecture
The fundamental notion is that one instruction may perform all loading, evaluating, and saving actions, just like a multiplication command can load, evaluate, and store data, which is why it’s difficult.
| RISC | CISC |
| It is a Reduced Instruction Set Computer. | It is a Complex Instruction Set Computer. |
| It Optimization of the instruction set is emphasized through software. | It emphasizes on hardware to optimize the instruction set. |
| It is a hard wired unit of programming in the RISC Processor. | Microprogramming unit in CISC Processor. |
| It requires multiple register sets to store the instruction. | It requires a single register set to store the instruction. |
| RISC has simple decoding of instruction. | CISC has complex decoding of instruction. |
| Uses of the pipeline are simple in RISC. | Uses of the pipeline are difficult in CISC. |
| It Utilizes a limited number of instructions that take less time to execute. | It Exercising the instructions requires more time because there are a lot of them. |
| It uses LOAD and STORE that are independent instructions in the register-to-register a program’s interaction. | It In memory-to-memory interaction, a program uses LOAD and STORE instructions. |
| RISC has more transistors on memory registers. | CISC has transistors to store complex instructions. |
| The execution time of RISC is very short. | The execution time of CISC is longer. |
| RISC architecture can be used with high-end applications like telecommunication, image processing, video processing, etc. | CISC architecture can be used with low-end applications like home automation, security system, etc. |
| It has fixed format instruction. | It has variable format instruction. |
| The program written for RISC architecture needs to take more space in memory. | Program written for CISC architecture tends to take less space in memory. |
| Example of RISC: ARM, PA-RISC, Power Architecture, Alpha, AVR, ARC and the SPARC. | Examples of CISC: VAX, Motorola 68000 family, System/360, AMD and the Intel x86 CPUs. |
