Problems in this exercise assume that logic blocks needed to implement a processors datapath have the following
Question:
1. If the only thing we need to do in a processor is fetch consecutive instructions (Figure 4.6), what would the cycle time be?
Figure 4.6
2. Consider a datapath similar to the one in Figure 4.11, but for a processor that only has one type of instruction: unconditional PC-relative branch. What would the cycle time be for this datapath?
3. Repeat 4.4.2, but this time we need to support only conditional PC-relative branches. The remaining three problems in this exercise refer to the datapath element Shift - left -2:
4. Which kinds of instructions require this resource?
5. For which kinds of instructions (if any) is this resource on the critical path?
6. Assuming that we only support beq and add instructions, discuss how changes in the given latency of this resource affect the cycle time of the processor. Assume that the latencies of other resources do not change.
Step by Step Answer:
Computer Organization and Design The Hardware Software Interface
ISBN: 978-0124077263
5th edition
Authors: David A. Patterson, John L. Hennessy