How to make a real random generator?

[vaf20]

Real Random Generator

hi
i have a table which includes dedicated numbers . i want to make up random address generator to get a random number between all of these numbers in table. how i can realize this random generator . u may be say that to use LFSR but note that LFSR is periodical random generator and random pattern repeat at special period so this not a real random generator.
i know there is no pure random generator but i am looking for better algorithm and simple preferly ...
can anyone help me ? any comment or idea !!!!
tnx

 

[echo47]

Real Random Generator

Maybe this will be helpful:
"Simple PLL-Based True Random Number Generator for Embedded Digital Systems"
**broken link removed**

 

[zorro]

Re: Real Random Generator

Hello vaf20,

If the LFSR is long enough that its period is much longer than the “memory” (ability to “remember the past”) of your system, it will be “seen” as a true random generator.
Take into account that if you need random numbers of N bits, no less than N clocks are needed between successive samples in order that they look independent if just a simple LFSR is used.
You can combine two or more LFSR of different lengths (e.g. EXORing their outputs), increasing the period.
Generators based in LFSR have good statistical properties and are very simple.
Regards

Z

 

[vaf20]

Re: Real Random Generator

tnx 2 eecho47 and zorro
can u guide me to True Randorm Generator for more stuffs and materials?
in closing i want to generate some random square pulse around 10% duty cycle. for example one time is a pulse with 10.3% duty cycle and another time is 9.8% duty .
tnx again