UG144 April 24
LogiCORE IP Gigabit Ethernet MAC
Gigabit Ethernet MAC v8.5 User Guide
Date Version Revision
Revision History
DIS Product
Table of Contents
Designing with the Core
Configuration and Status
Appendix C Calculating DCM Phase-Shifting
Schedule of Figures
1Block Diagram
2External Gmii Receiver Logic for Spartan-3, Spartan-3E,
Figure A-2Frame Transfer across LocalLink Interface
DIS Product
Schedule of Tables
Clocking and Resetting Interfacing to Other Cores
About This Guide
Guide Contents
Convention Meaning or Use Example
Conventions
Typographical
Preface About This Guide
Acronym Spelled Out
Online Document
List of Acronyms
Conventions
Vhdl
Preface About This Guide Acronym Spelled Out
Recommended Design Experience
Related Xilinx Ethernet Products and Services
Introduction
About the Core
Gemac Core
Specifications
Technical Support
Feedback
System Overview
Core Architecture
Core Components
Core Interfaces
Core Interfaces
Gmac Core with Optional Management Interface
Core Architecture
Core Interfaces
Transmitter Interface
Client Side Interface
Flow Control Interface
Receiver Interface
MAC Unicast Address Optional
Management Interface Optional
Physical Side Interface
Configuration Vector Optional
Asynchronous Reset
7Reset Signal Direction Clock Domain Description
Mdio Interface
Graphical User Interface
Generating the Core
Parameter Values in the XCO File
Output Generation
Generating the Core
Design Steps
Using the Example Design as a Starting Point
Designing with the Core
General Design Guidelines
11-Gigabit Ethernet MAC Core Example Design
Designing with the Core
General Design Guidelines
Know the Degree of Difficulty
Implementing the 1-Gigabit Ethernet MAC in Your Application
Make Only Allowed Modifications
Recognize Timing Critical Signals
Keep it Registered
Use Supported Design Flows
Normal Frame Reception
Using the Client Side Data Path
1Abbreviations Used in Timing Diagrams Definition
Receiving Inbound Frames
Rxgoodframe, rxbadframe timing
Using the Client Side Data Path
Receiving Inbound Frames
Frame Reception with Errors
Vlan Tagged Frames
Client-Supplied FCS Passing
Maximum Permitted Frame Length
Length/Type Field Error Checks
Enabled
Disabled
5Receiver Statistics Vector Timing
Receiver Statistics Vector
DIS Product
Length see Maximum Permitted Frame
Transmitting Outbound Frames
Transmitting Outbound Frames
Normal Frame Transmission
Padding
7Frame Transmission with Client-supplied FCS
Client Underrun
9Transmission of a Vlan Tagged Frame
Inter-Frame Gap Adjustment
Transmitter Statistics Vector
10Inter-Frame Gap Adjustment
Name
Bit 31 is equivalent to bit
Flow Control Requirement
Using Flow Control
Overview of Flow Control
Flow Control Basics
Using Flow Control
Overview of Flow Control
Pause Control Frames
Client Initiated Pause Request
Flow Control Operation of the Gemac
Transmitting a Pause Control Frame
Core-initiated Pause Request
Flow Control Operation of the Gemac
Receiving a Pause Control Frame
Core Initiated Response to a Pause Request
Client Initiated Response to a Pause Request
Method
Flow Control Implementation Example
4Flow Control Implementation Triggered from Fifo Occupancy
Flow Control Implementation Example
Using Flow Control
Gmii Transmitter Logic
Using the Physical Side Interface
Implementing External Gmii
1External Gmii Transmitter Logic
Using the Physical Side Interface
Implementing External Gmii
Gmii Receiver Logic
Spartan-3, Spartan-3E, Spartan-3A and Virtex-4 Devices
DCM Reset circuitry
3External Gmii Receiver Logic for Virtex-5 Devices
Virtex-5 Devices
Rgmii Transmitter Logic
Implementing External Rgmii
Implementing External Rgmii
Virtex-4 Devices
5External Rgmii Transmitter Logic in Virtex-4 Devices
6External Rgmii Transmitter Logic in Virtex-5 Devices
Rgmii Receiver Logic
7External Rgmii Receiver Logic
Virtex-4 Devices
8External Rgmii Receiver Logic for Virtex-4 Devices
9External Rgmii Receiver Logic for Virtex-5 Devices
10RGMII Inband Status Decoding Logic
Rgmii Inband Status Decoding Logic
Connecting the Mdio to an External PHY
Using the Mdio interface
Connecting the Mdio to an Internally Integrated PHY
Host Clock Frequency
Configuration and Status
Using the Optional Management Interface
2Configuration Registers Address Description
Configuration Registers
Configuration and Status
Receiver Configuration Word
Receiver Configuration
Using the Optional Management Interface
3Receiver Configuration Word Bit Default Description
Interframe Gap Adjust Enable If ‘1,’ the transmitter will
Transmitter Configuration
6Flow Control Configuration Word Bit Default Description
Flow Control Configuration
Address Filter Configuration
Mdio Configuration
12Address Filter Mode Bits Default Description
Writing and Reading to and from the Configuration Registers
10Address Table Configuration Word Bits Default Description
11 Address Table Configuration Word
1Configuration Register Write Timing
3Address Table Write Timing
Accessing the Address Table
Introduction to Mdio
Mdio Interface
5Typical MDIO-managed System
Write Transaction
Read Transaction
Accessing Mdio With Gemac
8MDIO Access through Management Interface
Pause frame MAC Source Address470
Access without the Management Interface
Transmitter Interframe Gap Adjust Enable
Receive Flow Control Enable . When this bit
Required Constraints
Constraining the Core
Constraining the Core
Period Constraints for Clock Nets
Required Constraints
Timespecs for Critical Logic within the Core
Gmii IOB Constraints
Constraints when Implementing an External Gmii
Timespecs for Reset Logic within the Core
1Input Gmii Timing Symbol Min Max Units
Gmii Input Setup/Hold Timing
Virtex-5 Devices
Non-Virtex-5 devices
Understanding Timing Reports for Gmii Setup/Hold Timing
Virtex-5 devices with Delayed Data/Control
Virtex-5 Devices with Delayed Clock
Rgmii IOB Constraints
Constraints when Implementing an External Rgmii
2Input Rgmii Timing Symbol Min Typical Units
Rgmii Input Setup/Hold Timing
Spartan-3, Spartan-3E, Spartan-3A, and Virtex-4 Devices
Rgmii DDR Constraints
Understanding Timing Reports for Rgmii Setup/Hold timing
106
4Timing Report Setup/Hold Illustration
108
With External Gmii
Clocking and Resetting
Clocking the Core
With Internal Gmii
Standard Clocking Scheme
Clocking and Resetting
Multiple Cores
With Rgmii
3Clock Management Logic with External Gmii Multiple Cores
Multiple Cores
4Clock Management Logic with External Rgmii Multiple Cores
Reset Conditions
Ethernet 1000Base-X PCS/PMA or Sgmii Core
Interfacing to Other Cores
Interfacing to Other Cores
Integration to Provide 1000BASE-X PCS with TBI
Ethernet 1000Base-X PCS/PMA or Sgmii Core
116
GTP
Virtex-5 LXT and SXT Devices
Clkdv
Virtex-5 FXT Devices
Ethernet Statistics Core
Ethernet Statistics Core
Integration to Provide Sgmii Functionality
120
Configuration Miim access Statistics Read
122
Synthesis
Using the Simulation Model
Implementing Your Design
Pre-implementation Simulation
Mapping the Design
Implementation
XST-Verilog
Generating the Xilinx Netlist
Generating a Bitstream
Post-Implementation Simulation
Placing-and-Routing the Design
Static Timing Analysis
Other Implementation Information
Using the Model
GMII/RGMII
Using the Client-Side Fifo
Transmit Fifo
Appendix a Using the Client-Side Fifo
Interfaces
Interfaces
Receive Fifo
Data Flow
Overview of LocalLink Interface
Functional Operation
Functional Operation
Clock Requirements
User Interface Data Width Conversion
Expanding Maximum Frame Size
Hardware Verification
Core Verification, Compliance, and Interoperability
Verification by Simulation
134
Finding the Ideal Phase-Shift
Calculating DCM Phase-Shifting
DCM Phase-Shifting
Appendix C Calculating DCM Phase-Shifting
Receive Path Latency
Core Latency
Transmit Path Latency
Appendix D Core Latency
tx_data_valid 
tx_ifg_delay[7:0] 
tx_statistics_vector[31:0] 
tx_statistics_valid 
pause_val[15:0] 
rx_data_valid 
rx_good_frame 
rx_bad_frame 
rx_statistics_vector[27:0] 
rx_statistics_valid 
host_opcode[1:0] 
host_addr[9:0] 
host_wr_data[31:0] 
host_rd_data[31:0] 
host_miim_sel 
host_req 
host_miim_rdy 
gmii_txd[7:0]
gmii_tx_en
gmii_tx_er
gmii_rx_clk
gmii_rxd[7:0]
gmii_rx_dv
gmii_rx_er
mdc
mdio_out
mdio_tri