Up Counter:
The counter which counts from 0 to finite value
Down Counter:
The counter which counts from finite value to 0
For a Design if both up and down counter works equally well, then which one should be selected?
Up counter will be the best option compared to the Down counter because we need a two’s complement circuit in down counter which takes extra logic. This increases the no of gates and power consumption.
In grey counter only one bit is toggled at each time and this counter is used in pointing the memory locations and simple way to remember the grey count seqeunce
4-bit grey Counter
0000 – 0 1101 – 12
0001 – 1 1111 – 14
0011 – 3 1110 – 13
0010 – 2 1010 – 9
0110 – 6 1011 – 10
0111 – 7 1001 – 8
0101 – 5 1000 – 7
0100 – 4
1100 – 11