Lecture 9 Objectives

KNOW:

• The programmer-visible components of the LC-3 ISA (Instruction Set Architecture)
• The three operate instructions in the LC-3 ISA

BE ABLE TO:

• Identify the components in the LC-3 data path (figure 5.18 in the text) that are affected by each of the LC-3 operate instructions
• Decode/encode any ADD, AND, or NOT instruction, given the LC-3 template for that instruction
• Build machine-code routines that define arithmetic and logical operations like "subtract" and "or" from LC-3 operate instructions

Sample Exam Question:

At some instant in time, the LC-3 registers contain these values:

R0 0000 0000 0000 0000

R1 0000 0000 0000 0000

R2 0000 0010 0001 0001

R3 0010 0010 0011 1111

R4 1111 1101 0000 0000

R5 0000 0000 0000 0000

R6 0000 0011 0010 1101

R7 1111 1111 1111 1111

Explain what the following LC-3 instruction will do. Be as explicit as you can using the information provided.

0110 000 010 111111