Low Latency 40G Ethernet Intel® FPGA IP User Guide: Agilex™ 5 FPGAs and SoCs

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ID 813652
Date 11/25/2024
Public
Document Table of Contents
Document Table of Contents x
1. About the Low Latency 40G Ethernet Intel® FPGA IP 2. Low Latency 40G Ethernet Intel® FPGA IP Parameters 3. Getting Started 4. Functional Description 5. Clocking and Reset Requirements 6. Interfaces and Signal Descriptions 7. Control, Status, and Statistics Register Descriptions 8. Comparison Between Various Low Latency 40G Ethernet Intel® FPGA IPs 9. Document Revision History for the Low Latency 40G Ethernet Intel® FPGA IP User Guide: Agilex™ 5 FPGAs and SoCs
1. About the Low Latency 40G Ethernet Intel® FPGA IP x
1.1. Low Latency 40G Ethernet Intel® FPGA IP Supported Features 1.2. Low Latency 40G Ethernet Intel® FPGA IP Device Family and Speed Grade Support 1.3. Resource Utilization 1.4. Release Information
1.2. Low Latency 40G Ethernet Intel® FPGA IP Device Family and Speed Grade Support x
1.2.1. Low Latency 40G Ethernet Intel® FPGA IP Device Family Support 1.2.2. Low Latency 40G Ethernet Intel® FPGA IP Device Speed Grade Support
3. Getting Started x
3.1. Introduction to Intel® FPGA IP 3.2. Installing and Licensing Intel® FPGA IPs 3.3. Specifying the IP Parameters and Options 3.4. Simulating the IP 3.5. Generated File Structure 3.6. Integrating Your IP in Your Design 3.7. Testbench 3.8. Compiling the Full Design and Programming the FPGA
3.6. Integrating Your IP in Your Design x
3.6.1. Pin Assignments 3.6.2. Placement Settings
3.7. Testbench x
3.7.1. Understanding the Testbench Behavior
4. Functional Description x
4.1. Low Latency 40G Ethernet Intel® FPGA IP Functional Description 4.2. GTS Transceiver Configuration 4.3. TX Datapath 4.4. RX Datapath 4.5. Flow Control 4.6. Link Fault Signaling Interface
4.3. TX Datapath x
4.3.1. TX MAC 4.3.2. TX PCS 4.3.3. PMA
4.3.1. TX MAC x
4.3.1.1. Preamble Insertion 4.3.1.2. Frame Padding 4.3.1.3. Inter-Packet Gap Generation and Insertion 4.3.1.4. Frame Check Sequence (CRC-32) Insertion 4.3.1.5. TX Avalon® Streaming Filter
4.4. RX Datapath x
4.4.1. RX MAC 4.4.2. RX PCS
4.4.1. RX MAC x
4.4.1.1. IP Core Preamble Processing 4.4.1.2. IP Core CRC Checking and Dynamic Forwarding 4.4.1.3. IP Core Strict SFD Checking 4.4.1.4. Length/Type Field Processing
4.4.1.4. Length/Type Field Processing x
4.4.1.4.1. Frame Type Checking 4.4.1.4.2. Length Checking
4.5. Flow Control x
4.5.1. TX Pause/PFC Flow Control Transmission 4.5.2. XON/XOFF Pause Frames
5. Clocking and Reset Requirements x
5.1. Clocks 5.2. Reset Requirements
6. Interfaces and Signal Descriptions x
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. GTS Transceivers Signals 6.6. GTS 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 6.12. GTS Reset Sequencer Intel® FPGA IP
7. Control, Status, and Statistics Register Descriptions x
7.1. PHY Registers 7.2. TX MAC Registers 7.3. RX MAC Registers 7.4. Pause/PFC Flow Control 7.5. Statistics Counters 7.6. Shadow Register
1. About the Low Latency 40G Ethernet Intel® FPGA IP
2. Low Latency 40G Ethernet Intel® FPGA IP Parameters
3. Getting Started
4. Functional Description
5. Clocking and Reset Requirements
6. Interfaces and Signal Descriptions
7. Control, Status, and Statistics Register Descriptions
8. Comparison Between Various Low Latency 40G Ethernet Intel® FPGA IPs
9. Document Revision History for the Low Latency 40G Ethernet Intel® FPGA IP User Guide: Agilex™ 5 FPGAs and SoCs

5.2. Reset Requirements

The reset controller has soft reset signals that are asserted by the CSR and three asynchronous resets that are asserted externally.
Reset Connection
The general reset signals reset the following functions:
  • soft_tx_rst,tx_rst_n: Resets the IP core in the TX direction. Resets the TX PCS and TX MAC. This reset leads to deassertion of the tx_lanes_stable output signal.
  • soft_rx_rst, rx_rst_n: Resets the IP core in the RX direction. Resets the RX PCS and RX MAC. This reset leads to deassertion of the rx_pcs_readyoutput signal.
  • sys_rst, csr_rst_n: Resets the IP core. Resets the TX and RX MACs, PCS, and transceivers.

In addition, the synchronous reconfig_reset signal resets the IP core transceiver reconfiguration interface, an Avalon® memory-mapped interface. Associated clock is the reconfig_clk, which clocks the transceiver reconfiguration interface.

Table 13.  Reset Signals FunctionsIn this table, a tick (√) represents the block is reset by the specified reset signal.
Reset/Module TX MAC RX MAC TX Packet Stats RX Packet Stats TX PCS RX PCS TX PMA RX PMA
csr_rst_n/sys_rst √ √ √ √ √ √ √ √
tx_rst_n/soft_tx_rst √       √      
rx_rst_n/soft_rx_rst   √       √    
reconfig_reset                

Reset Sequence or Initialization

The reset sequencing is handled by the core’s reset controller. Asserting a reset on the csr_rst_n signal triggers the reset sequence. When the csr_rst_n reset is asserted, the rx_pcs_ready and tx_lanes_stable signals go low and can only go back high after deasserting the reset.

The CSR register read/write must wait at least 2 clock cycles after the csr_rst_n release or assertion. Altera recommends waiting for 10 clock cycles. You can also reset the TX and RX datapaths independently by toggling tx_rst_n and rx_rst_n respectively.

Figure 10. Reset Sequence
Level Two Title