Sistem Berdigit
Logic Gates..
Logic gates process signals which represent true or false. Normally the positive supply voltage +Vs represents true and 0V represents false. Other terms which are used for the true and false states are shown in the table below. It is best to be familiar with them all.Logic states | |
True | False |
1 | 0 |
High | Low |
+Vs | 0V |
On | Off |
Gates are identified by their function: NOT, AND, NAND, OR, NOR, EX-OR and EX-NOR. Capital letters are normally used to make it clear that the term refers to a logic gate.
Note that logic gates are not always required because simple logic functions can be performed with switches or diodes:
- Switches in series (AND function)
- Switches in parallel (OR function)
- Combining IC outputs with diodes (OR function)
NOT gate (inverter)
The output Q is true when the input A is NOT true, the output is the inverse of the input: Q = NOT AA NOT gate can only have one input. A NOT gate is also called an inverter.
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Traditional symbol | Truth Table |
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AND gate
The output Q is true if input A AND input B are both true: Q = A AND BAn AND gate can have two or more inputs, its output is true if all inputs are true.
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Traditional symbol | Truth Table |
reti ke md duan oii..!! |
NAND gate (NAND = Not AND)
This is an AND gate with the output inverted, as shown by the 'o' on the output.The output is true if input A AND input B are NOT both true: Q = NOT (A AND B)
A NAND gate can have two or more inputs, its output is true if NOT all inputs are true.
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Traditional symbol | Truth Table |
OR gate
The output Q is true if input A OR input B is true (or both of them are true): Q = A OR BAn OR gate can have two or more inputs, its output is true if at least one input is true.
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Traditional symbol | Truth Table |
NOR gate (NOR = Not OR)
This is an OR gate with the output inverted, as shown by the 'o' on the output.The output Q is true if NOT inputs A OR B are true: Q = NOT (A OR B)
A NOR gate can have two or more inputs, its output is true if no inputs are true.
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Traditional symbol | Truth Table |
bomb...created by Nazri, hahah.. |
EX-OR (EXclusive-OR) gate
The output Q is true if either input A is true OR input B is true, but not when both of them are true: Q = (A AND NOT B) OR (B AND NOT A)This is like an OR gate but excluding both inputs being true.
The output is true if inputs A and B are DIFFERENT.
EX-OR gates can only have 2 inputs.
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Traditional symbol | Truth Table |
EX-NOR (EXclusive-NOR) gate
This is an EX-OR gate with the output inverted, as shown by the 'o' on the output.The output Q is true if inputs A and B are the SAME (both true or both false): Q = (A AND B) OR (NOT A AND NOT B)
EX-NOR gates can only have 2 inputs.
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Traditional symbol | Truth Table |
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comey kamu buat reja :D
REPLYwekk!!..comey apanya..:P
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