Bidirectional Signaling Using Component Mode - Bidirectional Signaling Using Component Mode - UG861

All 52 pins in a bank are capable of bidirectional operation using the same component primitives.

For bidirectional signaling with 3-state support, for the output and 3-state path use the solutions as discussed in ODDRE1. Note the 3-state path driving the T input for the IOBUF does not support simple registered outputs such as FDCE/FDPE/FDRE/FDSE. Registers for FDCE/FDPE/FDRE/FDSE for the 3-state path are implemented in internal logic.

For designs using an OSERDES, the following figure shows an example bidirectional pin with IDELAY and ODELAY. The OSERDES only supports combinatorial 3-state controls for the T input of the IOBUF.

Figure 1. Bidirectional Signaling Using IDELAY/ODELAY with ISERSDES and OSERDES

Bidirectional support varies by I/O bank. The following table lists the recommended bidirectional logic. When unsupported, the Vivado tool can borrow resources from additional I/Os.