Diffprobe prototype

Intro

This is the umbrella repo for a lot of my T&M projects. Some will end up in separate repos.

Project Codenames

Boards, subsystems, etc are all named after famous electrical engineers who made major contributions to the field of test equipment design.

Platform Architecture

All instruments are planned to share the same basic platform. Generally speaking, this platform will be:

Mechanical form factor

• 1U rackmount, depth dependent on the specific instrument.

Power

• 48V DC power on 6-pin Molex Mini-Fit Jr connector (back left)
• Intermediate bus converter based on the trigger crossbar IBC design to produce 12V output.
• Possible changes from current design (as of 2024-03-31): switch to bigger MCU with flash space for A/B firmware images, consider swapping main DC-DC module to something with lower standby power (current IBC wastes ~3W no-load which isn't great)
• STM32L0 based power/reset sequencing supervisor with soft power on/off

Software/firmware stack

• ngscopeclient as primary UI
• staticnet as TCP/IP stack
• Bare metal, no OS, no dynamic memory allocation
• SFTP based firmware update, eventually with signed updates (user can add new signing keys via uart console)

Main chipset

• STM32H7 as main processor running SCPI stack, sshd, and control plane functionality (low speed ADCs/DACs, GPIOs, etc)
• Xilinx UltraScale+ / UltraScale / 7 series FPGA as main datapath. Some instruments may have >1 FPGA.

Communications

• KSZ9031 based 10/100/1000 baseT fallback Ethernet interface
• 10Gbase-R SFP+ / 25Gbase-R SFP28 interface for primary remote control path
• Twinlan transport, SCPI control plane socket plus bare TCP socket for binary waveform data
• 2.13" monochrome e-ink display with IP/version/status information
• RS232 console on rear panel RJ45 (Cisco pinout)

RF / signal interface

• Front panel SMA/BNC probe ports. Number of channels dependent on PCB size.
• Rear panel SMA for 10 MHz reference in, level TBD
• May have reference out TBD
• May have PPS in/out TBD
• Rear panel trigger in/out if applicable

Roadmap (including external repos)

1. Trigger Crossbar
   Currently in progress. Not planning to make in volume, focus is on prototyping as much of the platform as possible to speed development and de-risk future projects. Prototype assembled, firmware dev in progress.

2. kup-lulz: One-off Kintex UltraScale+ test board on OSHPark 4 layers, using a sketchy reballed aliexpress FPGA. Intended as a low-risk validation for UltraScale+ based power, pcb footprint/schematic, and some RTL development. Schematic complete, fine tuning layout.

3. GROVER: Kintex UltraScale+ based 10/25G BERT. On hold until kup-lulz is brought up and working as it will essentially be a scaled-up version of the same design

4. VOLLUM (Howard Vollum, co-inventor of triggered-sweep oscilloscope)

   • No design progress yet, but can probably leverage some old frontend work. One 6 Gbps AD9213 is in inventory for a scaled down (7 series based) single channel prototype.
   • 2 GHz / 10 Gsps 12 bit oscilloscope, as many channels as I can fit in 1U
   • Per channel: 1x AD9213, frontend, XCAU25P-2FFVB676, 72-bit DDR4 LRDIMM
   • Top level: One more FPGA, details TBD, doing trigger sync and MSO channels
   • Will need to use parallel / bonded serial LVDS for waveform download since all 12 GTYs on the KU25Ps will be used for the JESD204

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Stuff below here is way old and needs to be redone

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General

• STARSHIPRAIDER: umbrella term for the entire project
• CLARKE (Edith Clarke, first female EE professor in USA): the original STARSHIPRAIDER project

Oscilloscopes

All are 8 channels??

• BLONDEL (Andre-Eugene Blondel, inventor of electromechanical oscillograph)
  8 bit: 100 MHz / 250 - 500 - 1000 Msps
  12 bit: 50 MHz / 125 - 250 - 500 Msps
  4 AFE : 1 HMCAD1520
  Two acquisition cards, 4 channels each
  One XC7A100T-2FGG676 on main board
  One DDR3 800 SODIMM on main board

• DUDDELL (William Duddell, inventor of moving-coil mirror oscillograph)
  250 MHz / 1 Gsps, 1 AFE : 1 HMCAD1520 1x XC7K160T-2FFG676

  Eight analog cards, one HMCAD1520 + one AFE each One digital card with 1-2 SFF-8087 connectors for LA One AWG card with a TBD JESD204 DAC using unused serdes lanes (assuming 4 for 40G, one for 10G, three available)

• ZENNECK (Jonathan Zenneck, inventor of electrically scanned CRT oscilloscope)
  500 MHz or 1 GHz / 5 Gsps, 1 AFE : 1 AD9213-6G

  Per channel:

  • 1x XC7A200T-2FFG1156
  • 1x AD9213 in 6G speed grade
  • 2x DDR3 800 SODIMM

  Global:

  • 1x XC7K160T-2FFG160T (could do six channels with direct lane to each one)

• VOLLUM (Howard Vollum, co-inventor of triggered-sweep oscilloscope)
  1-2 GHz / 10 Gsps, 1 AFE : 1 AD9213

• MURDOCK (Melvin Jack Murdock, co-inventor of triggered-sweep oscilloscope)
  6 GHz / 40 Gsps, 1 AFE : 4 AD9213

Probes / peripherals

• CONWAY (VLSI pioneer, co-author of Mead & Conway)
  8-bit comparator-to-LVDS logic analyzer pod with SFF-8087 interface and high-impedance inputs

• MEAD (other half of Mead & Conway)
  8-bit comparator-to-LVDS logic analyzer pod with SFF-8087 interface and 50 ohm inputs

• MAXWELL (James Clerk Maxwell, discovered Maxwell's Equations)
  Kintex-7 ISERDESE2 based LA

• TODO: Artix-7 GTP based LA??

• DENNARD (Robert Dennard, inventor of DRAM)
  Kintex-7 GTX based LA

• BRAUN (Karl Ferdinand Braun, inventor of optically scanned CRT oscilloscope and phased array) Low-bandwidth active probe ADA4817-1ACPZ-R7

Signal Generators

• FLEMING (John Ambrose Fleming, inventor of vacuum tube) 4 channel 14 bit 2.5 Gsps arbitrary waveform generator, AD9739 + Kintex-7 + DDR3 SODIMM based. Need ~160 Gbps of RAM bandwidth to keep them fed

  Two channels of 14-bit LVDS per DAC = 28 LVDS pairs for data, assume clock/sync are external to FPGA Slow control: 4 wire SPI, IRQ = 5 slow lines

  4x DAC = 84 pairs (168 pins used / 4 banks / 200 allocated) + 15 slow lines

  Two xc7k160t's, two dacs + 1 sodimm of ram on each

  4GB DDR3 SODIMM, 1 GB per channel = 512 Mpoints of waveform data Probably some digital outputs (mix of LVDS and LVCMOS, and maybe some slow pin headers?)