On Wed, 20 Oct 2010 15:45:35 -0700, Jim Thompson
wrote:

On Wed, 20 Oct 2010 17:23:54 -0500, John Fields
wrote:

On Wed, 20 Oct 2010 14:34:38 -0700, Jim Thompson
wrote:

I'd like to conjure up a random bit generator.

Just feed it a clock and have it generate random bits.

74HC... components preferred... I have most everything in that family
in my parts bin ;-)

---
Whoopeee!!!

Right up my alley!

Do you want truly random or pseudorandom, and if pseudorandom how long
do you want the output to be before it repeats?


---
JF

Pseudo-random is just fine. I just need it to test an
encoding/decoding chip design. A hundred bits or so before repeat
would be quite adequate. No security involved... just testing to be
sure of no decoding hiccups.

Try a 74hc164 and a 74hc7266. Connect QF and QG to A input through one
of the gates in the 7266. Apply clear and clock to 164. You should get
a 127 bit PRBS.
--
Muzaffer Kal

DSPIA INC.
ASIC/FPGA Design Services

http://www.dspia.com