Commit d553638f authored by Benoit Rat's avatar Benoit Rat

doc: add wrs connection and calibration section

  * Remove appendix
  * Update FAQ

TODO: calibration values does not correspond to this release
parent 613e9854
......@@ -556,7 +556,6 @@ you can't read the label on the second one, we suggest you to fill the input as
Enter S/N for board fmc-0b00 in the format xx-XXX (or 0) : 0
### Manual
If you prefer to perform these steps manually you can try the
......@@ -1380,10 +1379,76 @@ Advanced used
Connect to the WRS
Improve calibration
If you have a White Rabbit Switch ([WRS]), you should try to see
the synchronization between the [WRS] and the two [SPEC+FMCDIO] boards.
First you need to setup the two [SPEC+FMCDIO]s as `slave` by changing the
mode in the UART of each board.
wrc# ptp stop
wrc# mode slave
wrc# ptp start
Then you should run the [WRS] in master or grandmaster mode as explained
in [wr-switch-guide.pdf].
Finally you need to connect the slave SFPs (blue) to the [SPEC]s and the
master SFP (violet) to the switch.
The result of this experiment is illustrated by the next figure where
you can see the 3 PPS signals: yellow for [WRS], blue and violet for
![WRS PPS vs Starting Kit PPS](img/ssk_wrspps.jpg)
The distance between each PPS might be reduced by the improving the
calibration which is the subject of the next section.
When you compare the PPS of two [SPEC+FMCDIO] board you will find that they
are almost always synchronized without the need to calibrate the
gateware. However if you compare these PPS with the one of the switch
and you do not obtain a delay similar as the one in the WRS figure above
you might need to calibrate the [WRS] and the [SPEC+FMCDIO].
The value that you need to use can be found at the wiki page:
If you use a custom gateware or SFPs that are not listed in the wiki page
you should run yourself the calibration in order to obtain the correct values
for your setup.
> **Warning**: Cable length/type can modify around ~5ns/meter the delay
between the moment when the PPS was out of the board and when it was
captured by the oscilloscope.
> **Notes**: Please check that you are using the values that correspond
to your gateware release. When this document was generated we refer as
wr-nic-v2.0 (starting kit).
## List your actual sfp database
wrc# sfp show
## Erase the actual database if it was corrupted
wrc# sfp erase
## Add the parameters for the SFP provided in the starting kit
wrc# sfp add AXGE-1254-0531 46407 167843 73622176
wrc# sfp add AXGE-3454-0531 46407 167843 -73622176
Do not forget to also add these value to your other WR equipments (i.e, [WRS])
as explained in the wiki page.
You might also check the [wrpc.pdf] for extended explanations on how to run
yourself the calibration procedure.
SPEC+DIO as grandmaster
......@@ -1560,8 +1625,6 @@ You must have installed the following tools:
* Texinfo
For all these steps you can follow our guide [ohwr_development.pdf](ohwr_development.pdf)
Golden SPEC gateware
......@@ -1668,96 +1731,6 @@ make
You should finally obtain the bitstream to import in your [FMC] driver folder.
In the Appendix we include other information that may be of interest.
WRPC as grandmaster
In basic configuration your Master [SPEC] can use its internal
free-running oscillator as a time reference. However, you can also
discipline your Master [SPEC] with external 10 MHz and 1-PPS signal by
connecting them to the appropriate LEMO connectors of [FMC-DIO] board:
![Grandmaster setup](ssk_grandmaster.png)
The requirement for the applied signals are:
* ~[1.5V to 3V][^aroundval] without termination
* ~[2.5V to 4V] with 50Ohm termination.
* PPS pulse width must be at least one 10MHz period (>100ns).
[^aroundval]: These values are given on an indicative basis because they depend on the source and
connection you are using.
An example of typical signal generated for GM mode is displayed below:
* Green signal is PPS.
* Pink signal is 10MHz.
![Grandmaster signals](ssk_gm_signals.png)
Then in the wrc console just execute the following commands:
wrc# mode grandmaster
wrc# ptp start
And you should obtained:
SPLL_Init: running as GrandMaster, 1 ref channels, 2 out channels
PLL locking .................. LOCKED
For more information about grandmaster mode you can take a look at: [wr_external_reference.pdf].
This document has been written for the WR switch, but timing/accuracy/stability requirements are
similar for the SPECs.
### PCIe mode
By default the SPEC+DIO should be configured to be run in GM setup, but if you are not sure please
reset the default value. See [Default Mode](#default-mode) Section.
### Standalone mode
You can also run GM in a full standalone mode in order to transmit WR clock without the need of a PC.
First you need to flash the SPEC with the latest bitstream you can find the package:
To do so you need to generate a MSC file as follow:
Create PROM Files > SPI Flash > Single FPGA > 32M > MCS
And then, when asking for SPI/BPI, just add the `.msc` file and select
the corresponding SPI flash memory: `M25P32`.
* The setup of the cable is exactly the same as above, and you do not need to setup the mode because it is
correctly configured for GM by default at power up.
* Then you need to run grandmaster mode from wrc console, as above.
* (Optional) Finally, if you need to keep this configuration at power up, you can write a small script
on the EEPROM to boot in grandmaster mode.
wrc# init erase
wrc# init add ptp stop
wrc# init add sfp detect
wrc# init add sfp match
wrc# init add mode gm
wrc# init add ptp start
Please refer to *Writing EEPROM and calibration* Section of the [wrpc.pdf] document.
Frequently Added Questions
......@@ -1779,7 +1752,7 @@ Resume
However, you will find resume of the most asked questions below:
However, you will find a resume of the most asked questions below:
### I can't generate a PPS signal or any point in section 5 is not working
......@@ -1853,22 +1826,9 @@ After that the device keeps working as was previously specified.
### No SFP in EEPROM database
When you try to match your SFPs and you obtain an error such as **Could not match to DB** you
need to add your own SFP parameters.
## List your actual sfp database
wrc# sfp show
## Erase the actual database if it was corrupted
wrc# sfp erase
## Add the parameters for the SFP provided in the starting kit
wrc# sfp add AXGE-1254-0531 46407 167843 73622176
wrc# sfp add AXGE-3454-0531 46407 167843 -73622176
need to add your own SFP parameters. Please refer to the [Calibration Section](#calibration)
to understand how to add correct SFPs parameters.
You can also check the [wrpc.pdf] for extended explanations on how to obtain the parameters for your own SFP
and how to calibrate them.
### Modprobe is not working
Markdown is supported
0% or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment