Page 119 - A Practical Guide from Design Planning to Manufacturing

92 Chapter Three

step may create insurmountable problems for later steps in the design.
The real challenge of design is to understand enough of the steps before
and after your own specialty to make the right choices for the whole
design flow.

Key Concepts and Terms
Architecture Package and test cost
Circuit design Proliferation and compaction
Fab utilization Silicon debug
Layout Tapeout and first silicon
Lead design Validation
Logic design Variation and repackage
Microarchitecture Wafer and die yield

Review Questions

1. Describe the overall processor design flow.
2. What are the significance of tapeout and first silicon?
3. What are some common positions on a design team and their
responsibilities?
4. What are some common differences between high-end, mainstream,
and value desktop processors?
5. How are proliferations, compactions, and variations different from
lead designs?
6. Why is fab utilization important?
7. Using the assumptions of Table 3-6, what is the maximum die size
that gives a total processor cost below $100? What die size would
give the same processor cost using 300-mm wafers with processed
wafer cost of $4000?
8. Why are server processor die typically larger than desktop proces-
sor die?
9. [Discussion] Plan a processor design project. Describe the project
with the following: target market, previous design used as starting
point (if any), fabrication technology, total number of transistors, die
size, cost, design time.
10. [Discussion] Identify processor products currently being sold in
each of the following markets: high-end server, 1U server, high-end
desktop, value desktop, mobile desktop replacement, and mobile
handheld.