All things in all posts will help you visualize about the way that computers work generally. Note that it is not the real structure of modern computers, but the way that modern computers work is nearly the same as in my posts. I am sure that if you understand about the way that computers work in my posts, you will easy to learn about all fields of computer afterward. Thank you !!!
You knew about a byte in my previous post. It is a 8-bit memory in computers. If you want to control this byte (when that byte can be output and not output), you must use a special structure. This structure will output a byte when it is controlled “on”. And will not output a byte when it is controlled “off”. This device is called “Enabler”. Below is the picture about “Enabler”:
On the left of the picture, you can see the “Enabler” has eight AND gates. Each AND gate will have one “i” (input) input signal and one “e” (enable) input signal. This “i” input signal is connected to the corresponding “o” (output) output signal of one bit in a byte. And the “e” input signals of every AND gate are connected together.
On the right of the picture, you can see the simplified “Enabler” structure with corresponding “i” input signals, “e” input signal and “o” output signals. And the symbol “E” is short for “Enabler”.
So, you can imagine the way that the “Enabler” work like this: when one byte is set up with 8-bit in it, the output “o” of every bit (or the input “i” in the “Enabler”) will enter all AND gates in “Enabler”. If the “e” input signal is “off”, every bit in the byte will not be in the “o” output of the “Enabler”. But if the “e” input signal is “on”, only bits that have state “1” (“on”) will be in the “o” output signal of the “Enabler” and other bits will not be in (in state of “0”). For example, with a byte “0000 1111”, when “e” is “off”, you can see we have a byte “0000 0000” in the output of “Enabler” and when “e” is “on”, you can see we have a byte “0000 1111” in the output of “Enabler”. You can check it again.
You can see the “Enabler” is like a controller that allows and does not allow information in one byte to go through. With “e” is “1”, the byte can go through the “Enabler” or the byte is transferred in circuit. With “e” is “0”, the byte can not go through the “Enabler” or the byte is not transferred (held in the “o” output signal of that byte).
In the above diagram, you can see a separate “Enabler”. Now, we will combine a byte with a “Enabler” to see a complete structure. Look at the picture below to see this combination:
On the left of the picture, you can see a combination of a byte diagram and a “Enabler” diagram. All of them are easy to understand and I explained above. On the right of the picture, you can see the simplified diagram of this combination. “B” part and “E” part are combined to form “R” part. And “R” is short for “Register”.
This is all about a register in computers. Register can save and allow to transfer information of a byte. Sometimes, we will use only the “s” input signal without the “e” input signal because we can have registers that always allow bytes to go through. That registers only contain “byte” components but still are called “registers”.
And one thing more that I want you to know is that a register can only contain one byte at any given time. One new byte goes in register, previous byte will be lost. It may be easy to realize. Thanks for reading and see you later.
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