Please enable JavaScript.
Coggle requires JavaScript to display documents.
SYSTEMS ARCHITECTURE 1.1 - Coggle Diagram
SYSTEMS ARCHITECTURE 1.1
CPU
von Neumann architecture
A description of the processing architecture that all CPUs use. John von Neumann invented the processor architecture which stores a program in memory as instructions and executes them sequentially using the ALU, control unit and registers. This is known as the stored program concept.
-
Purpose of the CPU
The CPU is the Central Processing Unit. Its job is to fetch, decode and execute instructions
Basic Computer Model
A computer model consists of an input, an output, a CPU and a storage area. Data is input, processed and then either output or sent to secondary storage. It is held in primary memory while it is being processed.
The CPU receives instructions and data from an input or memory. The instructions and data are processed by the CPU and the results are either sent to an output or transferred to secondary storage.
Examples of input devices include a mouse or a keyboard whereas output devices are things like monitors, speakers and printers.
Embedded Systems
Many devices such as washing machines and cars have something called embedded systems. These appliances are programmed to behave in a certain way. For example, a washing machine generally won't turn on unless the door is fully closed or locked due to its programming.
Processor Components
Control unit
fetches, decodes and executes instructions
-
-
Registers
-
Current Instruction Register - the CIR holds the current instruction to be executed, which has been fetched from memory and is temporarily held in the MDR before being copied to the CIR
Memory Data Register - when the data or program instruction is fetched from memory, it is temporarily held in the MDR
Accumulator - the ACC is one of the general purpose registers in which data and results of many operations are temporarily stored
Memory Address Register - the MAR holds the address (location in memory) of the instruction or piece of data to be fetched or stored
Buses
Data bus - sends data between the processor, memory and input/output devices
-
-
-
Cache
Cache is an area where repeated instructions are kept. This is so that the computer takes less time to load