TMC-10115: High Fan-out Signal
Description
High fan-out nets limit the performance of designs using the Intel Hyperflex architecture. High fan-out may contain long or short path imbalances that limit retiming in critical chains.
Parameters
| Name | Description | Type | Default Value | Min Value | Max Value |
|---|---|---|---|---|---|
| fanout | Reports a violation for drivers that have at least the number of fan-outs specified in this parameter | integer | 50000 | 0 | |
| driver_name_filter | Reports a violation for high fan-out drivers that do not match any of the name patterns specified in this parameter. The list of patterns is space-separated. Patterns can contain wildcard characters '*' and '?', and hierarchy separator '|'. Wildcards do not match any hierarchy separator in a hierarchical name. To support natural specification of bus bit indices, square brackets '[', ']' in a pattern are treated as plain characters (they do not denote a set of characters). | string_list |
Recommendation
Duplicate high fan-out driver registers. Refer to DUPLICATE_REGISTER and DUPLICATE_HIERARCHY_DEPTH assignments for automated solutions. Alternatively, you can edit the RTL to create duplicate copies.
If you edit the RTL, apply the preserve_syn_only attribute to duplicate registers and assign the duplicates to individual instances in the fan-out hierarchy.
Severity
Low
Tags
| Tag | Description |
|---|---|
| register-duplication | Design rule checks related to duplication of registers in the design, either manually or automatically. |
Device Family
- Intel®Agilex™
- Intel®Stratix® 10