Avoid Multiple RPs Driving Same Static Leaf Cell - 2021.1 English

UltraFast Design Methodology Guide for Xilinx FPGAs and SoCs (UG949)

Document ID
UG949
Release Date
2021-08-18
Version
2021.1 English

Ensure that a specific static Endpoint (leaf cell) is connected to only one reconfigurable partition (RP). PPLOC reduction is triggered for a reconfigurable module (RM) pin only if the static Endpoint is placed in the expanded routing footprint of the RP. A leaf cell with individual leaf pins connected to multiple RPs can be placed in the expanded routing footprint of only one RP. Therefore, PPLOC reduction cannot occur on two RPs at the same time.

In the following example, two RPs are connected to the same static Endpoint. This approach is not recommended, because it negatively impacts routability.

Figure 1. Two RPs Driving the Same Static Endpoint

In the following example, two RPs each drive different static Endpoints. LUT1 is inserted to separate the static Endpoints. This approach is recommended for improved routability.

Figure 2. Two RPs Driving Different Static Endpoints