Embedded System - Hardware

Hardware is a general term for the physical artifact of technology. In embedded devices, all the electronics hardware resides on a board, also referred to as a printed circuit board(PCB). PCB often made of thin sheets of fiberglass. The major hardware components of the most board are Central processing unit(CPU) the master processor, memory where the system's software is stored, input devices input slave processors, output devices output slave processors and Bus interconnection the other components to another and provide pathway. Example of embedded system hardware is this ADIDAS shoe it is embedded with microprocessor that calculates the pressure between the runner's foot and the ground. Modern hardware stores typically sell equipment such as keys, locks, hinges, latches, corners, handles, wire, chains, plumbing supplies, tools, utensils, cutlery and machine parts, especially when they are made of metal.

Random-access memory (RAM) is a form of computer data storage. Today, it takes the form of integrated circuits that allow stored data to be accessed in any order ."Random" refers to the idea that any piece of data can be returned in a constant time, regardless of its physical location and whether or not it is related to the previous piece of data.

storage devices such as magnetic discs and optical discs rely on the physical movement of the recording medium or a reading head. In these devices, the movement takes longer than data transfer, and the retrieval time varies based on the physical location of the next item.

Microprocessor incorporates most or all of the functions of a computer's central processing unit (CPU) on a single integrated circuit (IC, or microchip). Other embedded uses of 4-bit and 8-bit microprocessors, such as terminals, printers, various kinds of automation etc.

Embedded microprocessors are not exactly very popular, but that is how computers started out. These processors are basically soldered onto the motherboard, making it nearly impossible to switch processors. Socket-based microprocessors are the most popular since they are easy to interchange with one another. If you want to replace a Socket 775 microprocessor, you just have to buy another Socket 775 processor, and that's the end of the story.

Reduced instruction set computing is a CPU design strategy based on the insight that simplified (as opposed to complex) instructions can provide higher performance if this simplicity enables much faster execution of each instruction. A computer based on this strategy is a reduced instruction set computer (also RISC). PIC is a family of Harvard architecture microcontrollers made by Microchip Technology, derived from the PIC1640[1] originally developed by General Instrument's Microelectronics Division. The name PIC initially referred to "Programmable Interface Controller". PICs are popular with both industrial developers and hobbyists alike due to their low cost, wide availability, large user base, extensive collection of application notes, availability of low cost or free development tools, and serial programming (and re-programming with flash memory) capability. A complex instruction set computer (CISC) is a computer where single instructions can execute several low-level operations (such as a load from memory, an arithmetic operation, and a memory store) and/or are capable of multi-step operations or addressing modes within single instructions. The STATUS register is of most importance to programming the PIC, it contains the arithmetic status of the ALU (

Arithmetic Logic Unit), the RESET status and the bank select bit for data memory. As with any register, the STATUS register can be the destination for any instruction. If the STATUS register is the destination for an instruction that affects the Z, DC or C bits, then the write to these three bits is disabled. These bits are set or cleared according to device logic. Furthermore, the TO and PD bits are not writable. Therefore, the result of an instruction with the STATUS register as destination may be different than intended. For example, CLRF STATUS will clear the upper-three bits and set the Z bit. This leaves the STATUS register as 000u u1uu (where u = unchanged). A memory-mapped file is a segment of virtual memory which has been assigned a direct byte-for-byte correlation with some portion of a file or file-like resource. This resource is typically a file that is physically present on-disk, but can also be a device, shared memory object

, or other resource that the operating system can reference through a file descriptor. Once present, this correlation between the file and the memory space permits applications to treat the mapped portion as if it were primary memory. memory map is a structure of data (which usually resides in memory itself) that indicates how memory is laid out. Memory maps can have a different meaning in different parts of the operating system.

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♣ Embedded systems are part of a bigger system.

♣ Embedded systems are small.

♣ Embedded systems programming is programming with resource

   constraints.