Hw01 - LSU EE 4720 Homework 1 Due 2 March 2011 Problem 1 The MIPS code below executes on the illustrated implementation The loop iterates for many

Info iconThis preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: LSU EE 4720 Homework 1 Due: 2 March 2011 Problem 1: The MIPS code below executes on the illustrated implementation. The loop iterates for many cycles. 29:26 25:0 IF + 29:0 = ID 15:0 NPC ME NPC 25:21 20:16 Addr Data Data rtv D In WB ALU rsv Addr Addr +1 EX ALU Mem Port Addr PC 30 15:0 rtv format immed dst MD 01 IMM Decode dest. reg 2’b0 2 Data Data Out In Addr Mem Port Data Out dst dst IR lw r2, 0(r5) LOOP: lw r1, 0(r2) lw r3, 0(r1) sw r3, 4(r2) bne r3, r0 LOOP addi r2, r3, 0 (a) Show a pipeline execution diagram for enough iterations to determine the CPI. Compute the CPI for a large number of iterations. (b) Show when each bypass path is used. Do so by drawing an arrow to a multiplexor input and labeling it with the cycles in which it was used and the register. For example, something like C10/r9 −→ to show that the input is used in cycle 10 carrying a value for r9. Problem 2: Continue to consider the pipeline and code from the previous problem. The store instruction and the branch could both benefit from a new bypass connection. (a) Show a new bypass connection for the store. (b) Indicate the impact of the new store bypass connection on critical path length. (c) Show a new bypass connection needed by the branch. (d) Indicate the impact of the new branch bypass connection on critical path length. (e) Suppose that the cost of the two bypass connections were equal and that both had no critical path impact. If only one could be added to an implementation which would you add? Base your answer not on the example code above, but on what you consider to be typical programs. 1 ...
View Full Document

This note was uploaded on 12/11/2011 for the course EE 4720 taught by Professor Staff during the Fall '08 term at LSU.

Ask a homework question - tutors are online