The Periphery to Core Register Placement and Routing Optimization (P2C) option specifies whether the Fitter performs targeted placement and routing optimization on direct connections between periphery logic and registers in the FPGA core. P2C is an optional pre-routing-aware placement optimization stage that enables you to more reliably achieve timing closure.
Note: The Periphery to Core Register Placement and Routing Optimization option applies in both directions, periphery to core and core to periphery.
Transfers between external interfaces (for example, high-speed I/O or serial interfaces) and the FPGA often require routing many connections with tight setup and hold timing requirements. When this option is turned on, the Fitter performs P2C placement and routing decisions before those for core placement and routing. This reserves the necessary resources to ensure that your design achieves its timing requirements and avoids routing congestion for transfers with external interfaces.
This option is available as a global assignment, or can be applied to specific instances within your design.
Figure 72. Periphery to Core Register Placement and Routing Optimization (P2C) FlowP2C runs after periphery placement, and generates placement for core registers on corresponding P2C/C2P paths, and core routing to and from these core registers.