Discussion:
HW5: shifter logic
(too old to reply)
[Instr] Albert Chae
2008-07-27 21:38:03 UTC
Permalink
Raw Message
You're right, it wasn't in the slides. The general idea is to chain
muxes together. Try doing Part 1 of Omar's worksheet here
http://inst.eecs.berkeley.edu/~cs61c-tl/notes/Week5b.pdf
and you should have an idea of how to do it in logisim.

Albert
I remember Albert talking about shifter logic in class.. but for the life
of me I can't find it in the slides. Did he just write that on the board
and I didn't write it down? I guess I can sorta envision just reconnecting
wires or something.. but how to iterate through multiple shifts is sort of
feeling intimidating right now.
[Instr] Albert Chae
2008-07-27 22:55:05 UTC
Permalink
Raw Message
I know I talked about it... Please refrain from giving away too many
specifics about your implementation on the newsgroup.

Albert
It isn't in the slides, but you did talk about it. I made a little diagram,
with only two bits, though. I wrote "Barrel Shifter" so I googled that and
http://www.cgl.uwaterloo.ca/~wmcowan/teaching/cs251/s08/pdf/shifter.pdf
Right now, I am making everything 4 bits. That isn't too unwieldy on one
subcircuit. I am thinking I need separate subcircuits for left and right
shift. I decided I am working on left shift and I just deleted my "sign
extend" bit from that.
THanks for the link and the prompt reply. I will take a look at that.
Post by [Instr] Albert Chae
You're right, it wasn't in the slides. The general idea is to chain
muxes together. Try doing Part 1 of Omar's worksheet here
http://inst.eecs.berkeley.edu/~cs61c-tl/notes/Week5b.pdf
and you should have an idea of how to do it in logisim.
Albert
I remember Albert talking about shifter logic in class.. but for the life
of me I can't find it in the slides. Did he just write that on the board
and I didn't write it down? I guess I can sorta envision just reconnecting
wires or something.. but how to iterate through multiple shifts is sort of
feeling intimidating right now.
Loading...