AXI Bridge for PCI Express v2.4
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PG055 June 4, 2014
Chapter 3:
Designing with the Core
Shared Logic
This new feature allows you to share common blocks across multiple instantiations. It
minimizes the amount of required HDL modifications. You can use your own system-level
clocking or reset circuit. You can modify some of these blocks due to system requirements
(for example, swapping a BUFG for a BUFH). You can instantiate multiple cores and share
'common/shared logic' from one core among all instantiated cores. This is only applicable
for Endpoint mode, and not Root Port mode.
In the Vivado Design Suite, the shared logic options are available in the
Shared Logic
page
when customizing the core.
There are four types of logic sharing:
•
•
•
•
Internal Shared GT_COMMON and Clocking
Shared Clocking
To use the share clocking feature, select
Include Shared Logic (Clocking) in example
design
option in the in the Shared Logic tab (
).
When this feature is selected, the mixed-mode clock manager (MMCM) instance is removed
from the pipe wrappers and is moved into the support wrapper of the example design. It
also brings out additional ports to the top level to enable sharing of the clocks.
You also have the option to modify and use the unused outputs of the MMCM.