Sir,
OK, That's the way I was marking. So there is no problem now.
Ashique
On Wed, 31 Oct 2001, Jose Nelson Amaral wrote:
> On Tue, 30 Oct 2001, Ashikur Rahman wrote:
>
> > Sir,
> > I a pretty confused with the correct answer. Say, for Low to high
> > transition in output, 1st gate needs a delay for H->L, 2nd gate H->L, 3rd
> > gate H->L and 4th gate L->H. Now if I use two levels max delay for first
> > two gates it will be 17 and I need to know the 1 level delay for other two
> > gates. But table contains no such delay for 1-level gates. Wha can I do?
> >
>
>
> Lets name the devices from left to right as G1, G2, G3, and G4.
>
> For a LOW-to-HIGH transition in the output of G4
>
> to occur you must have:
>
> a HIGH-to-LOW transition at the output of G3
> a HIGH-to-LOW transition at the output of G2
> a HIGH-to-LOW transition at the output of G1
>
> The meaning of the (2 levels) and (3 levels) on Table 5-2 is related with
> the internal design of the XOR gates themselves in the 74x86 (see next
> email). Thus the students had no way to know whether they should use the
> 2 levels row or the 3 levels row of the table, and we should accept
> it if they used either one:
>
> Thus if they used the 2 levels information, they should get
>
> tpLH + 3*tpHL = 23 + 3*17 = 74
>
> If they used 3 levels information:
>
> tpLH + 3*tpHL = 30 + 3*22 = 96
>
> Similarly:
>
> For a HIGH-to-LOW transition in the output of G4
>
> to occur you must have:
>
> a LOW-to-HIGH transition at the output of G3
> a LOW-to-HIGH transition at the output of G2
> a LOW-to-HIGH transition at the output of G1
>
> Resulting for 2 levels:
>
> tpHL + 3*tpLH = 17 + 3*23 = 86
>
> And for the 3 levels data:
>
> tpHL + 3*tpLH = 22 + 3*30 = 112
>
>
>
> > Ashique
>
>
>
> Cheers,
>
> Nelson
>
> /
> \ / / Jose Nelson Amaral - amaral@cs.ualberta.ca
> ) / ( Associate Professor
> / / \ Dept. of Computing Science - University of Alberta
> ( / ) Edmonton, Alberta, Canada, T6G 2E8
> \ O / Phone: (780)492-5411 Fax: (780)492-1071
> \ / http://www.cs.ualberta.ca/~amaral
> `----'
>
>
>
>
This archive was generated by hypermail 2.1.3 : Wed Nov 21 2001 - 15:50:13 MST