Project description

This project aims at distributing periodic (mainly clock) signals of arbitrary frequencies over a White Rabbit network. A clock is encoded at a master node and unidirectionally broadcast to any number of receiver nodes, which recover an in-phase copy of the original signal. Number of distributed clocks depends only on network bandwidth, required latency and acceptable accuracy level.

Possible applications in the accelerators are:

Beam-synchronous timing
RF clock distribution
RF or beam-synchronous signal acquisition

Requirements

Note*: this is just a preliminary specification for the proof-of-concept demo project, it may be modified.

Frequency range: 0 - 250 MHz (to be able to distribute 40.079 MHz LHC bunch crossing frequency and 200 MHz SPS RF clocks)
System must accept clocks with abrupt frequency changes (i.e. FSK modulation), such as the SPS RF clock for ions.
Required jitter: < 10 ps rms (10 Hz - 10 MHz). More jitter allowed for rapidly changing input clocks (e.g. SPS Ions).
Accuracy: < 1ns
Precision: < 100 ps
Hardware platform: FMC DDS on a SPEC carrier or SVEC carrier

Project repositories

Hardware (schematics/PCB design): FMC DDS Mezzanine project
Gateware (VHDL) is currently hosted in the Mock Turtle (a.k.a. WR Node Core) HDL repository:
> * VHDL DDS Core
> * Top level for the SPEC carrier
> * Top level for the SVEC carrier
Embedded software © is currently hosted in the Mock Turtle (a.k.a. WR Node Core) software repository

The Git repository in this project binds together the right versions of the respective hardware, softaware & gateware repos and scripts allowing to build and set up a WR DDS test system.

Documentation & HowTo-s

Contacts

Commercial producers

Creotech

General questions about project

Tomasz Włostowski - CERN

Status

Date	Event
01-04-2013	Project started.
03-04-2013	Specification ready.
10-04-2013	V0 schematics created & reviewed.
15-04-2013	FMC hardware order sent to company.
20-04-2013	Started VHDL/software development.
24-04-2013	Received & powered up 2 DDS mezzanines.
08-05-2013	First working demo design.
15-05-2013	2013 Demo presented on PH-ESE seminar.
20-10-2015	Mock Turtle-based RF distribution system presented on ICALEPCS' 2015.
01-12-2015	Project specification extended to include SPS ion RF clock.
20-01-2016	Successful simulation of distributing SPS ion RF clock using undersampling ADC.

Tomasz Wlostowski - 21 January 2016

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