Difference between revisions of "Computer"
m |
m (→Components of a computer) |
||
| Line 8: | Line 8: | ||
==Instructions== |
==Instructions== |
||
==Components of a computer== |
==Components of a computer== |
||
| − | There are |
+ | There are 6 types of components in a computer system: |
| + | |||
| − | * CPU (Brain) |
||
| + | 1) The CPU is the Brain. |
||
| − | * oscillator (crystal, RC oscillator or any other clock source), used to clock the CPU |
||
| + | |||
| − | * Program memory (ROM), Non volatile memory containing a list of instructions to execute sequentially by the CPU |
||
| + | 2) The Oscillator, or the Clock, is a crystal, RC oscillator, or any other clock source, used to regulate the timing of the CPU, also referred to as “clocking” the CPU. |
||
| − | * RAM (read/write memory. Typically volatile, so losing content at power down) |
||
| + | |||
| − | * Output units |
||
| + | 3) The Program Memory (ROM) is the non-volatile memory containing a list of instructions to be executed sequentially by the CPU. |
||
| − | * Input units |
||
| + | |||
| − | Of these 6 types, only the first three are actually required for a functioning computer. This computer will simply fetch instructions from program memory and execute them sequentially. |
||
| + | 4) The Output Unit sends data out. |
||
| − | Unfortunately, a computer consisting of no more than that will be completely useless, as it has not way to communicate with the outside world. In other words: |
||
| + | |||
| − | Whatever this basic computer does is completely irrelevant, as it can not be see by anyone and has no effect on the world at all. |
||
| + | 5) The Input Unit lets data in. |
||
| − | The next thing it needs is an Output unit. Now we can start to build a computer that can actually be used for some things. The uses are still very limited, as it does not have input and |
||
| + | |||
| − | memory, but still some things can be done, such as a clock (showing up time since power up) or a timer that beeps after a certain period of time, such as an egg timer. |
||
| + | 6) The RAM is read/write memory that is typically volatile, so its content is lost when the computer is powered down. |
||
| − | Adding inputs (such one or more buttons to adjust or reset the time) can make it more valueable. There can also be other inputs, such as a analog inputs, that have to go through |
||
| + | |||
| − | an ADC (Analog to Digital Converter), to measure things such as temperature. |
||
| + | The first three components are absolutely essential for a computer to function. With these components, the Clock will prompt the Brain to keep fetching instructions from the ROM and to keep executing them sequentially. Unfortunately, such a computer has no way to communicate. The results of its executed instructions cannot be seen by anyone and thus whatever it does is irrelevant to the outside world. |
||
| − | Adding RAM might be important when the little bit of short term memory in the CPU (The CU registers) are no longer sufficient to get the job done. |
||
| + | |||
| + | It needs is an Output Unit. By adding output we start to see a computer with some limited uses. It be used as a clock that displays the amount of time since powering up (but that resets when powered down) or it can serve as a timer that beeps after a certain period, like an egg timer. |
||
| + | |||
| + | Next we add an Input Unit. A simple addition is a button. In the above example the button resets the clock or timer. Other input devices measure things such as temperature. |
||
| + | |||
| + | As the complexity of the task increases, the short term memory in the CPU (the CPU register) will no longer be sufficient to get the job done. |
||
| + | |||
| + | Adding the sixth type of component, RAM, greatly increases functionality and completes the build-out of our basic computer system. |
||
==How does a computer work== |
==How does a computer work== |
||
Revision as of 22:27, 15 June 2019
A computer is a machine that carries out a sequence of instructions.
While most people think of computers as machines that only do information processing, such as Laptops and Servers, but there is also a category called "Embedded Computers" or Embedded Systems. In Embedded Systems, the computer is used for a very specific purpose, which is typically to control the device of which it is a part.
Embedded Systems span a wide range, from small medical devices, like hearing aids, blood pressure sensors, and pace makers, to household appliances, such as washers & dryers, refridgerators, and coffee makers, to automotive, industrial and aerospace applications.
Instructions
Components of a computer
There are 6 types of components in a computer system:
1) The CPU is the Brain.
2) The Oscillator, or the Clock, is a crystal, RC oscillator, or any other clock source, used to regulate the timing of the CPU, also referred to as “clocking” the CPU.
3) The Program Memory (ROM) is the non-volatile memory containing a list of instructions to be executed sequentially by the CPU.
4) The Output Unit sends data out.
5) The Input Unit lets data in.
6) The RAM is read/write memory that is typically volatile, so its content is lost when the computer is powered down.
The first three components are absolutely essential for a computer to function. With these components, the Clock will prompt the Brain to keep fetching instructions from the ROM and to keep executing them sequentially. Unfortunately, such a computer has no way to communicate. The results of its executed instructions cannot be seen by anyone and thus whatever it does is irrelevant to the outside world.
It needs is an Output Unit. By adding output we start to see a computer with some limited uses. It be used as a clock that displays the amount of time since powering up (but that resets when powered down) or it can serve as a timer that beeps after a certain period, like an egg timer.
Next we add an Input Unit. A simple addition is a button. In the above example the button resets the clock or timer. Other input devices measure things such as temperature.
As the complexity of the task increases, the short term memory in the CPU (the CPU register) will no longer be sufficient to get the job done.
Adding the sixth type of component, RAM, greatly increases functionality and completes the build-out of our basic computer system.
