A newer version of this document is available. Customers should click here to go to the newest version.
7.6. MAC Flow Control Interface
|   Signal Name  |  
       Width |   Description  |  
      
|---|---|---|
| i_tx_pause | 1 bit |   When asserted, directs the IP core to send a PAUSE XOFF frame on the Ethernet link. 
         Note: For 10GE/25GE channels, you should hold the i_tx_pause signal more than 205 ns to get the request captured by the MAC. 
           |  
      
| i_tx_pfc[7:0] | 8 bits |   When a bit is asserted, directs the IP core to send a PFC XOFF frame on the Ethernet link for the corresponding priority queue. 
         Note: For 10GE/25GE channels, you should hold the i_tx_pfc signal more than 205 ns to get the request captured by the MAC. 
          The rising edge triggers the request. You must maintain this signal at the value of 1 until you want the IP core to end the pause period. The IP core sends a PFC XOFF frame after it completes processing of the current in-flight TX packet, and periodically thereafter, until you deassert the i_tx_pfc bit. When you deassert the bit, the IP core sends a PFC XON frame on the Ethernet link for the corresponding priority queue. This signal is functional only if priority flow control is enabled.  |  
      
| o_rx_pause | 1 bit |   When asserted, indicates the IP core received a PAUSE XOFF frame on the Ethernet link.  |  
      
| o_rx_pfc[7:0] | 8 bits |   When a bit is asserted, indicates the IP core received a PFC XOFF frame on the Ethernet link for the corresponding priority queue.  |