SPRUIL1D May 2019 – December 2024 DRA829J , DRA829J-Q1 , DRA829V , DRA829V-Q1 , TDA4VM , TDA4VM-Q1
There are five rules that can each set and clear a PFC (Priority based Flow Control) trigger condition for each enabled priority. The five rules are the destination based rule, the sum of outflows rule, the sum of blocks per port rule, the sum of blocks total rule, and the top of receive FIFO rule. Ethernet ports issue transmit PFC pause frames when any priority is triggered for any rule. Port 0 issues flow control on the associated receive thread when any priority is triggered for any rule. There are no pause frames sent on port 0 transmit (no port 0 outflow). Receive priority remapping is taken into account for all rules on all ports. Transmit priority remapping is taken into account for the sum of outflows rule, the sum of blocks per port rule, and the destination based rule. Transmit priority remapping is not taken into account for the sum of blocks total rule or the top of receive FIFO rule. The intent of PFC is to shutdown lower priorities as traffic congestion increases so that the higher priorities can continue to operate. Systems with only 1518 byte packets may only need to configure the destination based rule.