TX Flow Control Error Handling
The PCIe Controller detects the following errors and reports them as flow control protocol errors:
- An RX that does not support scaled flow control must never cumulatively issue more than 2,047 data payload outstanding unused credits to the TX or 127 unused header credits. Additionally The RX must never cumulatively issue more outstanding unused data or headers to the TX than the maximum credit values based on the scaled flow control scaling factors. The PCIe Controller checks for violations of this rule and reports a Flow Control Protocol Error (FCPE).
- If scaled flow control is activated for a virtual channel, the HdrScale and DataScale fields in the UpdateFCs must match the values advertised during initialization. The PCIe Controller checks for violations of this rule and reports a Flow Control Protocol Error (FCPE).
The PCIe Controller does not support infinite credit advertisement.