Page 118 - A Practical Guide from Design Planning to Manufacturing

Design Planning 91

TABLE 3-8 Examples of Cost Breakdown
Mainstream processor Server processor
Die cost 64% 84%
Package & assembly 29% 13%
Test 7% 3%

the processor contributed approximately 20 percent to the cost of a typ-
ical $1000 PC. 10 If sold at $200 our desktop processor example costing
only $54 would show a large profit, but our server processor example at
$198 would give almost no profit. Producing a successful processor
requires understanding the products it will support.

Conclusion
Every processor begins as an idea. Design planning is the first step in
processor design and it can be the most important. Design planning
must consider the entire design flow from start to finish and answer sev-
eral important questions.

What type of product will use the processor?
What is the targeted performance and power of the design?
What will be the performance and power of competing processors?
What previous design (if any) will be used as a starting point and how
much will be reused?
How long will the design take and how many designers are needed?
What will the final processor cost be?

Errors or poor trade-offs in any of the later design steps can prevent
a processor from meeting its planned goals, but just as deadly to a proj-
ect is perfectly executing a poor plan or failing to plan at all.
The remaining chapters of this book follow the implementation of a
processor design plan through all the needed steps to reach manufac-
turing and ultimately ship to customers. Although in general these
steps do flow from one to the next, there are also activities going on in
parallel and setbacks that force earlier design steps to be redone. Even
planning itself will require some work from all the later design steps to
estimate what performance, power, and die area are possible. No single
design step is performed entirely in isolation. The easiest solution at one

10
Hennessy et al., Computer Architecture, 21.