# help me pleas "asynchronous binary up counter "

Discussion in 'Homework Help' started by mmu, Dec 25, 2005.

1. ### mmu Thread Starter New Member

Dec 25, 2005
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i know that might be easy , this is a one question in my assignment that i couldnot solve , i know how to design a 5-bit counter that count 0 to 31 but i donot know how to mae it from 0 to 29 pleas help me this is the question :

a) Design a 5-bit asynchronous binary up counter that counts from 0 to 29 using T flip-flops. Briefly explain and draw the circuitry of the design [3 marks].

B) Design a 5-bit parallel-in parallel-out shift register using D flip-flops to store the 5-bit asynchronous binary up counter outputs. Briefly explain and draw the complete circuitry of the design including the counter and register [2 marks].

2. ### maja New Member

Dec 22, 2005
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you pull to the each Rd : Q0*Q2*Q3*Q4.There's another way,but it's too ugly.

3. ### mmu Thread Starter New Member

Dec 25, 2005
4
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dear maja thanx but i didnot get ur answer can explain it more pleas

4. ### peajay Well-Known Member

Dec 10, 2005
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> i know how to design a 5-bit counter that count 0 to 31 but i donot know how to mae it from 0 to 29

Well, I have no idea what a T flip-flop is, but generally the way you make a counter count to a specific number is to connect some logic gates to it so that when it reaches the number after that number, it resets to zero. So you'd use like a 4-input AND gate connected to bits 1 though 4, ignoring bit 0, so that when the counter reaches 30 the output of the AND gate becomes 1, which triggers the counter to reset to 0. I'm pretty sure that works on asynchronous counters as well as synchronous ones.

5. ### mmu Thread Starter New Member

Dec 25, 2005
4
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thank u very much peajay , i'm working on it now and i hope it will work

if any one has another answer for part A and any answer for B plz help me ASAP
THANX IN ADVANCED

6. ### maja New Member

Dec 22, 2005
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There are 5 flip-flops(ff) T0,T1..Name the ff outs with Q0,Q1..,Q4.Binary representation of 29 is 11101 ,so you pull Q4 AND Q3 AND Q2 AND(NOTQ1)AND Q0,an that's the signal(S) to reset the counter.If it doesn't have Clear or Reset,you simulate it with T0=(Q0 AND S)OR(something that's already connected to T0 input).
Maby this will help:

7. ### mmu Thread Starter New Member

Dec 25, 2005
4
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thank u very much maja and peajay , finall i am able to solve the question