HC4GX15 Datasheet, PDF (181/668 Pages) Altera Corporation – HardCopy IV Device Handbook

Chapter 1: HardCopy IV Design Flow Using the Quartus II Software
Quartus II Settings for HardCopy IV Devices
Figure 1–5. Start I/O Assignment Analysis
Stratix IV: EP4SGX110F ...
1–13
The default output drive strength in the Quartus II software might not be appropriate
for your application. Altera recommends verifying the correct output drive strength
for the design. Assigning the right output drive strength improves signal integrity
while achieving timing requirements. In addition, the output capacitance loading for
both the output and bidirectional pins must be set in the I/O assignment for a
successful HardCopy compilation.
Physical Synthesis Optimization Settings
When you develop a HardCopy IV device with the Quartus II software, you can
target physical synthesis optimizations to the FPGA architecture in Stratix IV-device
first flow or the HardCopy architecture in the HardCopy IV-first flow. The
optimizations in the base revision are mapped to the companion device architecture
during the mapping process and the post-fitting netlists of both devices are generated
and compared. Therefore, you must have the identical physical synthesis settings for
both the HardCopy IV ASIC and Stratix IV FPGA revisions in order to avoid revision
comparison failure.
To enable Physical Synthesis Optimizations for the Stratix IV FPGA revision of the
design, on the Assignments menu, click Settings. In the Settings dialog box, in the
Category list, expand Fitter Settings. These optimizations are passed into the
HardCopy IV companion revision for placement and timing closure. When designing
with a HardCopy IV device first, you can enable physical synthesis optimizations for
the HardCopy IV device, and these post-fit optimizations are passed to the Stratix IV
FPGA revision.
© January 2010 Altera Corporation
HardCopy IV Device Handbook, Volume 2