SPRUI30H November 2015 – May 2024 DRA745 , DRA746 , DRA750 , DRA756
Each of the three CPSW_3G ports has an identical associated FIFO. Each FIFO contains a single logical receive queue and four logical transmit queues (priority 0 through 3). Each FIFO memory contains 20,480 bytes (20k) total organized as 2560 by 64-bit words contained in a single memory instance. The FIFO memory is used for the associated port transmit and receive queues. The TX_MAX_BLKS field in the FIFOs associated Px_MAX_BLKS register determines the maximum number of 1k FIFO memory blocks to be allocated to the four logical transmit queues (transmit total). The RX_MAX_BLKS field in the FIFO's associated Px_MAX_BLKS register determines the maximum number of 1k memory blocks to be allocated to the logical receive queue. The TX_MAX_BLKS value plus the RX_MAX_BLKS value must sum to 20 (the total number of blocks in the FIFO). If the sum were less than 20, then some memory blocks would be unused. The default is 17 (decimal) transmit blocks and three receive blocks. The FIFOs follow the naming convention of the Ethernet ports. Host Port is Port0 and External Ports are Port1 and Port2.