White Rabbit Switch with LJD prepared hardware

An 18-port White Rabbit switch V3.4 that is prepared for the Low-Jitter Daughterboard.

The changes compared to the V3.4 switch fall into two categories:

• replace existing components due to obsolescence
• changes to allow easy installation of a Low-jitter-daughterboard

SCB3.4.1

Component layout of the SCB3.4.1

Changes compared to the SCB 3.4:

1. J3 (the black connector on the left) is always fitted to connect a 'low jitter daughterboard' and J5 & J6 are added.
2. J6 is a u.FL connector to which the clock output of the Low-jitter-daughterboard can be connected.
3. J5 is used to select between the existing oscillator or the Low-jitter-daughterboard.
4. Replacement of obsolete components (most notably a different NAND flash)

Backplane (carrier board) 3.3.1

The backplane has been modified so the fans are always on (in the original backplane 3.3 design the fans are controlled by software). This keeps the hardware cooled in all circumstances.
Also more sturdy SFP cages have been used.

Low-jitter-daughterboard

A Low-jitter-daughterboard gives a significant improvement when it comes to the jitter performance of the White Rabbit switch.

Binaries

The following pre-packaged firmware files are available:

• Regular firmware v5.0.1 with support for SCB3.4.1
• Low-jitter-daughterboard firmware v5.0.1 with support for SCB3.4.1

Patches

• Linux kernel and Barebox patches to add support for the new (1Gbyte) NAND flash.

Documents

• Detailed hardware and software changes
• Design files in the OPNT_3.4.1 branch of the wr-switch-hw project.

Contacts

Commercial producers

• White Rabbit Switch - OPNT, The Netherlands

Status

11 May 2020