Thursday, December 30, 2010

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
10
HighLow
+Vs0V
OnOff


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 A
A NOT gate can only have one input. A NOT gate is also called an inverter.

traditional NOT gate symbol
Input AOutput Q
01
10
Traditional symbol
Truth Table




kat Lab BPS..JKE

AND gate

The output Q is true if input A AND input B are both true: Q = A AND B
An AND gate can have two or more inputs, its output is true if all inputs are true.
traditional AND gate symbol
Input AInput BOutput Q
000
010
100
111
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.
traditional NAND gate symbol
Input AInput BOutput Q
001
011
101
110
Traditional symbolTruth 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 B
An OR gate can have two or more inputs, its output is true if at least one input is true.
traditional OR gate symbol
Input AInput BOutput Q
000
011
101
111
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.
traditional NOR gate symbol
Input AInput BOutput Q
001
010
100
110
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 trueQ = (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.
traditional EX-OR gate symbol
Input AInput BOutput Q
000
011
101
110
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.
traditional EX-NOR gate symbol
Input AInput BOutput Q
001
010
100
111
Traditional symbol
Truth Table

2 comments:

Yunna Nordin said...

comey kamu buat reja :D

md duan said...

wekk!!..comey apanya..:P