fouadalnoor
Member
Hello guys,
I am trying to fully understand how to design a divide by 3 counter myself.
I do understand most of the theory behind why its "divide by n" but I find it a little confusing sometimes.
To design a divide by 3 counter I did the following (correct me if i'm wrong)
1. I Drew an ASM Chart with 3 states. I am using two outputs on my D-type Edge triggered (positive) bistable.
2. I made a truth table (with present/next state) and then got my equations for the inputs (Da and Db)
I got the following Equations:
Da = Qa(Bar)Qb + QaQb(bar)
Db = Qa(bar)Qb(bar)+QaQb(bar)
3. I drew up the circuit and got it looking as shown in the attached picture.
- It Does work and counts up to three as in 00, 01, 10,11,00... etc
The thing I am a little confused about is that in a divide by 3 it's supposed to be High 1/3 of the time right? Would my design be wrong as it's only off when its 00? If my design is correct please explain exactly how its "divide by 3" (Does it simply mean dividing the input frequency by 3 which means it will only count up to 3?)
Thanks for your help!
Fouad.
Thanks!
I am trying to fully understand how to design a divide by 3 counter myself.
I do understand most of the theory behind why its "divide by n" but I find it a little confusing sometimes.
To design a divide by 3 counter I did the following (correct me if i'm wrong)
1. I Drew an ASM Chart with 3 states. I am using two outputs on my D-type Edge triggered (positive) bistable.
2. I made a truth table (with present/next state) and then got my equations for the inputs (Da and Db)
I got the following Equations:
Da = Qa(Bar)Qb + QaQb(bar)
Db = Qa(bar)Qb(bar)+QaQb(bar)
3. I drew up the circuit and got it looking as shown in the attached picture.
- It Does work and counts up to three as in 00, 01, 10,11,00... etc
The thing I am a little confused about is that in a divide by 3 it's supposed to be High 1/3 of the time right? Would my design be wrong as it's only off when its 00? If my design is correct please explain exactly how its "divide by 3" (Does it simply mean dividing the input frequency by 3 which means it will only count up to 3?)
Thanks for your help!
Fouad.
Thanks!