Compact Universal Timing Endpoint Based on White Rabbit with Dual Ports
1.Introduction
The Cute-WR-DP is the enhanced version of Cute-WR with dual WR ports,The two ports can act in different modes:
1) parallel mode (Cute-WR-DP-PM)
In PM mode both port acts as down-link port connect to different WRS,
provide redundancy to improve the relibility for safety related
applications. Two WRPC work simultaneously on each port, the switch over
efforts developed on WRS can be adapted.
2) chain mode(Cute-WR-DP-CM)
In CM mode, two ports act as one down-link and one up-link to support
cascade topology. With deeper modification to WR technology
(show-stopper I am not aware may exist), more attractive features can be
explored like ring topology, on-the-fly data transmission, reflective
memory (GE property though). The possibilities can be remarkable.
The CUTEWR-DP board can also be used as normal WR node when only one port is used. Check the Github to get more information.
2.Hardware
2.1 Snapshot
CUTEDP-Board.jpg
2.2 Features:
- 3.3v power supply, DC Power Plug Jack or FMC or Pmod
- Standard FMC form;
- Two WR compatible SFP sockets;
- Spartan 6 (XC6SLX45T-4CSG324C);
- 32MBit SPI FLASH (M25P32-VMF6P);
- 64Kbit I2C EEPROM (24AA64T-I/MC);
- FMC LPC interface;
- Addition Low-cost connector on FMC Region3
- JTAG and RS232;
- External CLK reference (work in master mode);
- Adjustable CLK output (optional)
- 2 USER IO on front panel, LEMO interface
- 2 front panel LEDs;
- 2 Pmod Interfaces for debug
- 2 LEMO Interfaces for debug
2.2 Design Files
git clone https://github.com/leehongming/cutewr_dp_hw.git
3. Firmware
3.1 Structure Design
CUTEWR-DualPortDEMO.png
3.2 Design Files
git clone --recursive https://github.com/leehongming/cutedp.git
4.Demo
The Demo contains one WR switch and three CUTEWR-DP boards. The WR
switch acts as the Grandmaster(Layer 1) in this small network, and three
CUTEWR-DP boards are connected one by one. They are in Layer 2/3/4 of
this network seperately.
In each board, use the blue SFP (AXGE-1254-0531) in SFP0 and red SFP
(AXGE-3454-0531) in SFP1. (The label of each SFP is on the PCB)
Use the command below to change the parameters of each port.
- The SFP_PN is AXGE-1254-0531 or AXGE-3454-0531 if you use the SFPs produced by AXCEN.
- The port is 0 or 1.
- The units of dtx_value and drx_value are picosecond.
- alpha value is depended on your fiber.
sfp erase
sfp add SFP_PN port dtx_value drx_value alpha_value
Use the command below to set the IP of each port.
- command "ip set ip_addr" will set the ip address of port 0. The ip address of port 1 will be ip address of port 0 adds 1.
ip set ip_addr_port0
Use the command below to start or stop the PTP of each port.
ptp start (start both two ports)
ptp start 0/1 (start the selected port)
ptp stop (stop both two ports)
ptp stop 0/1 (stop the selected port)
Use the command "gui" to get the PTP status of each port.
The results are shown as
below:
The demo synchronization results are shown as below, C1(yellow) is the
WR switch while C2/C3/C4 are CUTEWR-DP
boards:
5. Current status
Date | Event |
26-Mar-2014 | Start of project. Conceptual Idea. |
25-Jan-2017 | Hardware verified |
25-Jan-2017 | Publish the simple dual port demo |
6. Users list
7. Acknowledgements
7s WR_LEN project