Cross-Coupled Nor Gate Cell and Cross-Coupled Nand Gate Cell - Electronic Circuits Projects Diagrams Free

shermaine · 22nd March 2004, 05:02 PM

Hello,

How does a cross-coupled nor gate and nand gate cell functioned?
Pls advise.
Thanks.

Russlk · 22nd March 2004, 10:22 PM

They become a set-reset flip-flop. Do you have a specific question?

shermaine · 23rd March 2004, 12:31 AM

How to determine when it is set, reset or remain?
Pls advise.
I dun understand how the croo-coupled works?

Russlk · 23rd March 2004, 04:08 AM

First, you have to understand how the NAND gate works. When both inputs are positive (high), the output is low. When either input is low, the output is high. In the diagram below, if both A in and B in are low, both outputs will be high. That is not a useful state. If both inputs are high, then A out and B out cannot both be high and both outputs cannot be low either. So, one has to be high and the other low. You don't know which is which unless you force it by taking either A or B low, then you know which output is high. OK?

shermaine · 24th March 2004, 01:40 PM

what if Aout is Q(bar) and Aout is Q?
Does the ouput depends on the input coming from Aout also?
Pls advise.
Thanks.

Russlk · 24th March 2004, 11:49 PM

Did you mean Bout is Q? The output only depends on whether Ain or Bin is taken low. The state of the output before that is not important.

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22nd March 2004, 05:02 PM	#1
shermaine	Cross-Coupled Nor Gate Cell and Cross-Coupled Nand Gate Cell Hello, How does a cross-coupled nor gate and nand gate cell functioned? Pls advise. Thanks.

22nd March 2004, 10:22 PM	#2
Russlk	They become a set-reset flip-flop. Do you have a specific question? __________________ see my website: www.geocities.com/russlk

23rd March 2004, 12:31 AM	#3
shermaine	How to determine when it is set, reset or remain? Pls advise. I dun understand how the croo-coupled works?

23rd March 2004, 04:08 AM	#4
Russlk	First, you have to understand how the NAND gate works. When both inputs are positive (high), the output is low. When either input is low, the output is high. In the diagram below, if both A in and B in are low, both outputs will be high. That is not a useful state. If both inputs are high, then A out and B out cannot both be high and both outputs cannot be low either. So, one has to be high and the other low. You don't know which is which unless you force it by taking either A or B low, then you know which output is high. OK? Attached Thumbnails __________________ see my website: www.geocities.com/russlk

24th March 2004, 01:40 PM	#5
shermaine	what if Aout is Q(bar) and Aout is Q? Does the ouput depends on the input coming from Aout also? Pls advise. Thanks.

24th March 2004, 11:49 PM	#6
Russlk	Did you mean Bout is Q? The output only depends on whether Ain or Bin is taken low. The state of the output before that is not important. __________________ see my website: www.geocities.com/russlk