11 October Day 14
CSC425 review
I. CPU
A. ALU
B. CU
C. Cache
A. ALU – arithmetic/logic unit
performs processing
contains circuitry to add, etc
issues: representation of numbers
base 2 binary form
1. integers – works well, except for … negative values as no way to
have a (-) sign in a bit!
a. signed magnitude
+3 +(-2) =
b. one’s complement
c. two’s complement
2. reals / floats
SES implementation – no way to have a (.) radix (decimal) point in a
bit!
B. CU – control unit
runs S/W
manager of system
1. instruction cycle
a. Fetch
b. Decode
c. Execute
2. Instruction sets
CSC 490 Course Notes and Outline, © Dr. Gary Locklair, Fall 2006
