Receive Data Path; Rx Engine; Rx Fifo; Figure 3: Receive Data Path - Broadcom NetXtreme/NetLink BCM5718 Series Programmer's Manual

BCM5718 Programmer's Guide

Receive Data Path

RX Engine

The receive engine (see
RX Rx
Rules Checker
Engine FIFO
The receive engine performs the following four functions:
• Moves the data from the PHY to an internal FIFO
• Moves the data from the FIFO to NIC internal memory
• Classifies the frame and checks it for rules matches
• Performs the offloaded checksum calculations

RX FIFO

The RX FIFO provides elasticity while data is read from PHY transceiver and written into internal memory. There
are no programmable settings for the RX FIFO. This FIFO's operation is completely transparent to host
software.
Broadcom
®
January 29, 2016 • 5718-PG108-R
Figure 3) activates whenever a packet arrives from the PHY.

Figure 3: Receive Data Path

Fram e
Buffers
N IC Jum bo RX Producer Ring
Em pty BD
N IC Standard RX Producer Ring
Em pty BD
Full BD
Receive Data Path
H ost Jum bo RX Producer Ring
Host Standard RX Producer
Ring
D M A
D M A
Host RX
Return
Ring
List
Initiator
DM A
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