220.127.116.11.2. Output and Output Enable Paths
Each output path contains two stages of DDIOs, which are half-rate and full-rate.
The difference between the output path and output enable (OE) path is that the OE path does not contain full-rate DDIO. To support packed-register implementations in the OE path, a simple register operates as full-rate DDIO. For the same reason, only one half-rate DDIO is present.
The OE path operates in the following three fundamental modes:
- Bypass—the core sends data directly to the delay element, bypassing all DDIOs.
- Packed Register—bypasses half-rate DDIO.
- SDR output at half-rate—half-rate DDIOs convert data from full-rate to half-rate.