<- previous    index    next ->

Lecture 5, Instructions and Registers

Get paper handout, fill in values for registers and memory
as we discuss the instructions in this lecture.
The program starts with PC set to address zero.
The instructions are defined on cs411_opcodes.txt

part1.asm
part1.abs

part1.abs
address  instruction    assembly language

00000000 8C010078 	lw   $1,w2($0)
00000004 8C02007C 	lw   $2,w3($0)
00000008 00000000 	nop
0000000C 00000000 	nop
00000010 00221820 	add  $3,$1,$2
00000014 00222022 	sub  $4,$1,$2
00000018 00012BC2 	sll  $5,$1,15
0000001C 00023403 	srl  $6,$2,16
00000020 0003380B 	cmpl $7,$3
00000024 0022580A 	and  $11,$1,$2
00000028 0022600D 	or   $12,$1,$2
0000002C AC010080 	sw   $1,w4($0)
00000030 1C080074 	addi $8,w1
00000034 00000000 	nop
00000038 00000000 	nop
0000003C 8D090004 	lw   $9,4($8)
00000040 1D0A0008 	addi $10,8($8)
00000044 00000000 	nop
00000048 00000000 	nop
0000004C AD430000 	sw   $3,0($10) 
00000050 00000000 	nop
...
00000070 00000000 	nop
00000074 11111111 w1:	word 0x11111111
00000078 22222222 w2:	word 0x22222222
0000007C 33333333 w3:	word 0x33333333
00000080 44444444 w4:	word 0x44444444


After the CPU has executed the first instruction:
General Registers                          RAM memory
                                            initial    final
 $0   00000000
      --------
 $1   22222222                     00000074  11111111
      --------                               --------  ____________
 $2                                00000078  22222222
     ______________                          --------  ____________
 $3                                0000007c  33333333
     ______________                          --------  ____________
 $4                                00000080  44444444
     ______________                          --------  ____________
 $5                                00000084  xxxxxxxx
     ______________                          --------  ____________
 $6
     ______________
 $7
     ______________
 $8
     ______________
 $9
     ______________
$10
     ______________
$11
     ______________
$12
     ______________


This is part of your project: part1.abs
and the result of running that small program part1.chk: 

part1.chk

Note the large amount of information printed each clock time.
Note that it takes 5 clock cycles to finish an instruction.

Basic MUX Truth Table and Schematic



How MUX are used to route data



You can see much of the code for the above in the
starter code for Proj1:
part1_start.vhdl

There are basic design principles for computer architecture
and many apply to broader applications.

Design Principle 1: 

       Simplicity is best achieved through regularity.

       A few building blocks, used systematically, will have
       fewer errors, be available sooner and sell for less.
       A uniform instruction set allows better compilers.

Design Principle 2:

       Smaller is faster:

       Smaller feature size means signals can move faster.
       Shorter paths, less stages, allow completion sooner.

Design Principle 3:

       Good design requires good compromises.

       There are no perfect architectures. There are kluges.

Design Principle 4:

       Make the common part fast.
       Amdahl's law, be sure you are maximizing speedup.


Pentium 4 Hyper threading

Intel Core Duo

AMD quad core, one core shown

$329 for just 1/2 quad core processor

a 4 CPU, 8GB RAM configuration
Now 12-core 16GB RAM, 3 hard drives, 2 DVD writers

Practice safe computing!

Beware Malware, Spyware and Adware:

Do everything you can to keep malware from infecting your systems,
malware authors do all they can to keep their work from being
detected and removed. By looking at the methods that malware uses
to keep itself safe, you can better root it out and remove 
it before the damage is done. Downloading attachments is the
primary way malware gets into your system.


HW3 assigned

    <- previous    index    next ->

Other links

Go to top