Sunday, October 11, 2009 11:27 PM,

A student writes:



	 My study group has put off question one until now because we were 
	 unsure of the meaning of part B. In one sense, a central controller of 
	 the individual logic circuits would need all of the bits handled by 
	 the individual circuits and thus the number is unchanged, OR the 
	 central machine would just need a flag that the state has changed in 
	 which case only 7 would be needed.
	 
	 If you could clarify what exactly needs storing beyond the bits needed 
	 to record the specified information, that would be great.
	 
	 Thanks,
	 <<name withheld to protect the student struggling with the scoreboard>>



I have no idea where your number 7 is coming from.

Let's change the example to something much simpler, but conveys the important 
essence.  Suppose the scoreboard had only two fields instead of sevem fields, 
one that had 35 possible states and one that had
3 possible states.  How many total possible states can be represented on the 
scoreboard?

If I control this with a central controller, how many bits do I need to 
represent all possible states?

If I control the two fields separately, how many bits to represent the state 
of the first field?  how many to represent the state of the second field?  
Therefore, how many in total if I do the two fields separately?

Good luck on the midterm.

Yale Patt