Comments for Room 514

Comment on JK & T Flip-Flops by James Grover

James Grover — Tue, 05 May 2009 22:36:24 +0000

Here is the general approach. Draw truth table with desired inputs, actual flip-flop inputs, followed by actual flip-flop output. Fill in the middle column(s) last. As an example, convert D flip-flop to T flip-flop. The combinational logic between the T and Q(t) produces D. Note Q(t) is the present output and Q(t+1) is the next output.

T Q(t) D Q(t+1)
0 0 0 0 No Change
0 1 1 1 No Change
1 0 1 1 Toggle
1 1 0 0 Toggle

To fill in D column decide what D needs to be to get the desired output Q(t+1).

Therefore D = (NOT T AND Q(t)) OR (T AND NOT Q(t) or D = T
XOR Q(t).

Or for the T to SR discussed above see the table below. Note the R=S=1 is teated as a don’t care since this condition should never occure.

S R Q(t) T Q(t+1)
0 0 0 0 0 No Change
0 0 1 0 1 No Change
0 1 0 0 0 Reset
0 1 1 0 0 Reset
1 0 0 1 1 Set
1 0 1 0 1 Set
1 1 x x x Not Allowed

Which simplifies to T = Q(t) AND S by K-maps

Comment on Understanding Layer Modes by chris

chris — Mon, 09 Feb 2009 19:06:01 +0000

magical

Comment on Representing Negative Numbers in Binary by mryantho

mryantho — Fri, 17 Oct 2008 03:02:04 +0000

Basically we who “program” the computer (using let’s say an assembly language) would agree that we are using say 8 bit negative numbers. So every 8 bits is a number with the leftmost bit representing its sign (positive or negative.) Of course this means that we have 0000000-1111111 (7 digits) as a range for positive and negative numbers.

Using 8 bit numbers isn’t much good nowadays. Now most computers use 64 bit registers (remember when 64 bit Windows XP came out?)

Comment on Representing Negative Numbers in Binary by conan

conan — Wed, 15 Oct 2008 01:29:45 +0000

?If we say 1001 is negative 6 then how do we get the computer to agree that it isn’t 8? ?Or 1110 to represent negative 5 and not 14?

In short, ?how do we get the computer to register negative numbers?

Comment on JK & T Flip-Flops by khatatbeh

khatatbeh — Wed, 16 Jul 2008 16:15:06 +0000

thnx a lot
I have a Q that I hope to find the answer of it sooooooon
how I can to design a JK flip flop using SR flip flop
show (truth table , k map,and the final equation)
note:
I wanna the design without convert SR flip flop to D flip flop
I mean I wanna JK flip flop directly from SR flip flop

Comment on Programming & Ruby Test Tomorrow by mryantho

mryantho — Tue, 06 May 2008 15:44:34 +0000

I find the spelling mistake in the graph witty and that it adds something special.

Comment on The Lightweight Introduction to Programming by mryantho

mryantho — Wed, 02 Apr 2008 02:28:40 +0000

The WoW Bard may be an April Fool’s joke.

Comment on The Lightweight Introduction to Programming by Rikko

Rikko — Wed, 02 Apr 2008 02:27:26 +0000

See the new WoW Class? Bard? Its pwnage, its like guitar hero on World of Warcraft.

http://www.worldofwarcraft.com/wrath/features/bard/bardclass.xml

Check how ridiculous this is sir….

Comment on The Lightweight Introduction to Programming by mryantho

mryantho — Wed, 02 Apr 2008 02:24:18 +0000

Yes Rikko, your teacher has skills. Like bow hunting skills.

Comment on The Lightweight Introduction to Programming by Rikko

Rikko — Wed, 02 Apr 2008 02:19:08 +0000

Yeah our teacher is the best!