To execute instructions, a computer's processor must generate the control signals used to perform the processor's actions in the proper sequence. A computer is a Machine that manipulates data according to a list of instructions. This sequence of actions can either be executed by another processor's software (for example in software emulation or simulation of a processor) or in hardware. Hardware methods fall into two categories: the processor's hardware signals are generated either by hardwired control, in which the instruction bits directly generate the signals, or by microprogrammed control in which a dedicated microcontroller executes a microprogram to generate the signals. Microprogramming (ie writing microcode) is a method that can be employed to implement Machine instructions in a CPU relatively easily often using less
Before microprocessors, hardwired control usually was implemented using discrete components, flip-chips, or even rotating discs or drums. A microprocessor incorporates most or all of the functions of a Central processing unit (CPU on a single Integrated Flip chip, also known as Controlled Collapse Chip Connection or its acronym C4, is a method for interconnecting Semiconductor devices such as This can be generally done by two methods.
Method1:The classical method of sequential circuit design. It attempts to minimize the amount of hardwire,in particular ,by using only log2p flip flops to realize a p state circuit.
Method2:An approach that uses one flipflop per state and and is known as one hot method. While expensive in terms of flip flops,this method simplifies controller unit design and debugging.
In practice,processor control units are often so complex that no one design method by itself can yield a satisfactory circuit at an acceptable cost. The most acceptable design may consist of several linked,but independently designed,sequential circuits.
Microprogramming made it possible to re-wire, as it were, a computer by simply downloading a new microprogram to it. Microprogramming (ie writing microcode) is a method that can be employed to implement Machine instructions in a CPU relatively easily often using less This required dedicated hardware or an external processor. For example, some of DEC's PDP-10 processors used a PDP-11 as a front-end which uploaded a microprogram to the main processor at boot time. Digital Equipment Corporation was a pioneering American company in the Computer industry The PDP-10 was a Mainframe computer manufactured by Digital Equipment Corporation (DEC from the late 1960s on the name stands for "Programmed Data Processor The PDP-11 was a series of 16-bit Minicomputers sold by Digital Equipment Corp Front-end and back-end are generalized terms that refer to the initial and the end stages of a process To download is to receive data from a remote or central system such as a Webserver, FTP server, mail server or other similar systems In Computing, booting ( booting up) is a bootstrapping process that starts Operating systems when the user turns on a Computer system
Traditionally, a sewing machines' stitch patterns and a washing machine's wash programs were implemented as hardwired, usually mechanical, controls. A sewing machine is a textile machine used to stitch Fabric or other material together with Thread. A washing machine, or washer, is a machine designed to clean Laundry, such as Clothing, Towels and sheets The term is mostly applied In modern machines, these are instead implemented as software which controls a computer which controls the machine hardware. This makes it possible, for example, to download additional stitch patterns for a small fee or upgrade a machine without having to buy a complete new machine. It also opens up for intellectual property rights issues. Intellectual property ( IP) is a legal field that refers to creations of the mind such as musical literary and artistic works inventions and symbols names