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bi directional shift register!

Posted: Fri Jun 20, 2003 1:56 am
by 1202
Ok will this work?

e.g. a 74ls299 bi directioanl shift register!

Ok I hear that bi directional shift registers have a hold feature, does this mean - can I write data to the parallel lines as input (then hold that data) and then clock it out serially.

e.g. I have a e2prom setup(other circuit), I put the e2prom in read mode and the bi directional shift register latches the data! I then disable the e2prom - effective 0 volts on its data lines right!!

can I therefore hold that data I read before on the bi directional shift register and clock it out serially without loosing it - I'm guessing this will work so long as I disable chip select on the e2prom before doing so.

thoughts?

Its just an enhancement I want to make to my homemade programmer hopefully.

:roll:

update! Note:

Posted: Fri Jun 20, 2003 2:08 am
by 1202
Note I want to know if this is ok because I want to use the same clock for both my address network and the bi directional shift register for the data network.

again I'm thinking of once the e2prom is setup, have it in readmode CS enabled!

the data then goes to the bi directional shift register, I then CS disable! (I then want to know if this data will stay latched ok on the chip and then use the clock to serially shift it out the other end)

thanks!
:roll:

might do the same idea with 2 ICS

Posted: Fri Jun 20, 2003 2:21 am
by 1202
It's proven easier and cheaper for me to get 2 IC's

serial to parallel & vise versa.

same idea though..

Posted: Fri Jun 20, 2003 6:18 am
by GARTHWILSON
What do you plan to connect the serial end of the shift registers to?

reply to what do you plan?

Posted: Sun Jun 22, 2003 7:16 am
by 1202
Parallel port - I have another Idea, I'll get back to you.

I'm going to use..

Posted: Sun Jun 22, 2003 9:01 am
by 1202
I'm going to use 74ls165 which has clocking input latch