e1-tracer¶

This page is about the "production" version of the setup described in ICE40_based_passive_tap.

It is a bi-directional, high-impedance passive tap for E1 (PRI/S2M) tracing. It traces both directions of a link simultaneously via two LIU (Line Interface Units) attached to an iCE40 FPGA with E1 framer + USB softcores.

The traces are sent as isochronous USB transfers to the host PC, where they can (for example) be stored on disk.

hardware¶

Hardware files can be found at: https://git.osmocom.org/osmo-e1-xcvr/tree/hardware/eagle and are available as Open Source Hardware.

design files¶

We originally started with a prototype from an iCE40 evaluation board plus two osmo-e1-xcvr and one e1-tap as described in ICE40_based_passive_tap.

Meanwhile, we have designed a fully integrated board. Design files are part of the osmo-e1-xcvr.git repository.

• Schematics:
  • EAGLE: source:hardware/eagle/e1-tracer.sch
  • PDF: source:hardware/e1-tracer_sch.pdf
• Board layout
  • EAGLE: source:hardware/eagle/e1-tracer.brd
  • PDF: source:hardware/e1-tracer_brd.pdf
  • Gerber: source:hardware/gerber
• Bill of Materials
  • gnumeric spreadsheet: source:hardware/e1-tracer_eBOM.gnumeric
  • CSV export: source:hardware/e1-tracer_eBOM.csv

gateware + firmware¶

The FPGA gateware and RISC-V softcore firmware are found in the e1-recorder branch of ice40playground.git, see https://github.com/smunaut/ice40-playground/tree/e1-recorder

availability¶

Fully assembled products based on this hardware are going to be made available by sysmocom

software¶

The host software is found in the e1-recorder branch of ice40playground.git, see https://github.com/smunaut/ice40-playground/tree/e1-recorder/projects/riscv_usb/sw

There are two related programs:

• main - the program used to perform recordings and store them
• dump - the program to analyze recordings