Low Latency 40G for ASIC Proto Ethernet Intel® FPGA IP User Guide
ID
683221
Date
11/10/2022
Public
1. About the Low Latency 40G for ASIC Proto Ethernet Intel® FPGA IP
2. Low Latency 40G for ASIC Proto Ethernet IP Core Parameters
3. Getting Started
4. Functional Description
5. Reset
6. Interfaces and Signal Descriptions
7. Control, Status, and Statistics Register Descriptions
8. Debugging the Link
9. Ethernet Toolkit Overview
10. Low Latency 40G for ASIC Proto Ethernet Intel® FPGA IP User Guide Archives
11. Low Latency 40G for ASIC Proto Ethernet Intel® FPGA IP Revision History
3.1. Installing and Licensing Intel® FPGA IP Cores
3.2. Specifying the Low Latency 40G for ASIC Proto Ethernet IP Core Parameters and Options
3.3. Simulating the IP Core
3.4. Generated File Structure
3.5. Integrating Your IP Core in Your Design
3.6. Low Latency 40G for ASIC Proto Ethernet IP Core Testbench
3.7. Compiling the Full Design and Programming the FPGA
6.1. TX MAC Interface to User Logic
6.2. RX MAC Interface to User Logic
6.3. TX PCS Interface to User Logic
6.4. RX PCS Interface to User Logic
6.5. Transceivers Signals
6.6. Transceiver Reconfiguration Signals
6.7. Avalon® Memory-Mapped Management Interface
6.8. Miscellaneous Status and Debug Signals
6.9. Reset Signals
6.10. Clocks
6.11. Flow Control Interface
4.1.1. Low Latency 40G for ASIC Proto Ethernet Core TX MAC Datapath
The TX MAC module receives the client payload data with the destination and source addresses. It then adds, appends, or updates various header fields in accordance with the configuration specified. The MAC does not modify the destination address, the source address, or the payload received from the client. However, the TX MAC module adds a preamble, if the IP core is not configured to receive the preamble from user logic. It pads the payload of frames greater than eight bytes to satisfy the minimum Ethernet frame payload of 46 bytes. The TX MAC module inserts IDLE bytes to maintain an average IPG of 12.
Figure 7. Typical Client Frame at the Transmit InterfaceIllustrates the changes that the TX MAC makes to the client frame. This figure uses the following notational conventions:
- <p> = payload size, which is arbitrarily large
- <s> = number of padding bytes (0–46)
- <g> = number of IPG bytes