Low Latency Ethernet 10G MAC Intel® FPGA IP User Guide: Agilex™ 5 FPGAs and SoCs
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5.6. Avalon® Streaming Flow Control Signals
| Signal | Operating Mode | Direction | Width | Description | 
|---|---|---|---|---|
| avalon_st_pause_data[] | All | In | 2 |   This signal takes effect when the register bits, tx_pauseframe_enable[2:1], are both set to the default value 0. 
        Set this signal to the following values to trigger the corresponding actions. 
          
  |  
     
| avalon_st_tx_pfc_gen_data[] | 10G | In |  n  (4–16)  |  
       n = 2 x Number of PFC queues parameter.  Each pair of bits is associated with a priority queue. Bits 0 and 1 are for priority queue 0, bits 2 and 3 are for priority queue 1, and so forth. Set the respective pair of bits to the following values to trigger the specified actions for the corresponding priority queue. 
  |  
     
| avalon_st_rx_pfc_pause_data[] | 10G | Out |  n  (2–8)  |  
       n = Number of PFC queues parameter.  When the MAC RX receives a pause frame, it asserts bit n of this signal when the pause quanta for the n th queue is valid (Pause Quanta Enable [n] = 1) and greater than 0. For each quanta unit, the MAC RX asserts bit n for eight clock cycle. The MAC RX deasserts bit n of this signal when the pause quanta for the n th queue is valid (Pause Quanta Enable [n] = 1) and equal to 0. The MAC RX also deasserts bit n when the timer expires.  |