Protocols
Back-Pressure
A flow control mechanism where a receiver signals that it cannot accept more data, causing the sender to pause transmission.
Detailed Explanation
Back-pressure prevents data loss when a downstream block is slower than upstream. In valid-ready protocols, de-asserting ready creates back-pressure. The upstream must hold data stable until ready returns. This propagates through a pipeline, potentially stalling sources.
Effective back-pressure handling is crucial for robust designs. Buffers (like skid buffers or FIFOs) can absorb temporary back-pressure without stalling upstream. Credit-based flow control is an alternative that pre-allocates buffer space.