H-Tile Hard IP Ethernet Intel® FPGA IP User Guide: Stratix® 10 Devices

ID 683430
Date 4/09/2024

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Document Table of Contents

B.5.37. Forward Flow Control Frames

Offset: 0x706

Forward Flow Control Frames Fields

Bit Name Description Access Reset
0 rx_pause_fwd Forward Flow Control Frames
Sets whether PAUSE and PFC frames are sent to the MAC Client Interface
  • 1: Forwards all flow control frames to the application
  • 0: Does not forward flow control frames that match the RX destination address for flow control to the application
Be careful when turning off Flow Control frame forwarding
  • This feature requires EHIP to be in a mode with the MAC turned on
  • When flow control forwarding is turned off, flow control frames are dropped regardless of whether flow control processing is turned on
  • Packets are considered to be flow control if they have T/L = 16'h8808, MAC Control opcode =0x0001 (PAUSE) or 0x0101 (PFC) and their destination address matches rx_pause_daddr
  • Flow Control packets are only processed by the MAC if they are also exactly 72 bytes long (including Preamble) and are error free
  • When Flow Control forwarding is turned off, Flow control packets are dropped and not processed
  • When this setting is changed, the RX MAC must be reset
  • At power-on, this register defaults to 0
  • When i_csr_rst_n is asserted, this register is set to the value given by the module parameter forward_rx_pause_requests
RW 0x0