Digital Signal Processing Reference
In-Depth Information
reconfigurable logic as the heart of a design, allows it to be reprogrammed to
implement a wide range of systems and designs. Extending the life of a board
design even one generation can result in significant savings and can largely
offset the increased per-unit expense of reconfigurable devices.
Table 15.2 Comparing SOPC, ASIC, and FixedProcessor Design Modalities
Feature
SOPC
ASIC
Fixed-Processor
S/W Flexibility
Z
Z
Z
Z
{
{
H/W Flexibility
Reconfigurability
Z
{
{
Development
Time/Cost
Z
{
Z
Peripheral
Equipment Costs
Z
Z
{
}
Z
Z
Performance
Z
9
Production Cost
}
Z
Power Efficiency
{
Z
Z
Legend
:
Z
- Good;
}
- Moderate;
{
- Poor
The SOPC approach is ideal for student projects. SOPC boards can be used and
reused to support an extremely wide range of student projects at a very low
cost. ASIC development times are too long and mask setup fees are too high to
be considered for general student projects. A fixed-processor option will often
require additional hardware and perhaps even a new printed circuit board
(PCB) design for each application. Given the complexity of today's multilayer
surface mount PCB designs, it is highly unlikely that students would have
sufficient time and funds to develop a new printed circuit board for a design
project.
15.5 An Example SOPC Design
The SOPC-based autopilot system seen in the photograph on the first page of
this chapter and the sensor board that mounts below it (described earlier in
Section 13.5) makes an interesting case study in SOPC design
10
. The autopilot
system continuously reads in sensor data that indicates attitude, altitude, speed,
and location. It then uses this data to solve the control system motion equations
for the aircraft and then outputs updated signals to control the aircraft.
9
In very large quantities.
10
Henrik B. Christophersen; R. W. Pickell; James C. Neidhoefer; Adrian A. Koller; Suresh K. Kannan;
Eric N. Johnson, “A Compact Guidance, Navigation, and Control System for Unmanned Aerial Vehicles”,
Journal of Aerospace Computing, Information, and Communication,
pp.,1542-9423, vol.3 no.5.
