This page documents a simple Command Module for the Apollo blade family for test purposes. Something similar to the original mechanical prototype (green board) in photo below.

Goals:

• Create a solid KiCAD PCB design with correct mechanics
• Inexpensive test board for development of firmware, front panels, etc
• Power supply loading test (with large heatsinks, resistors etc to dissipate ~ 200+W

Questions for discussion:

• What should the scope of the first board be? Maybe only mechanics since PCB are so cheap?
• What FPGA to use? See below.
• Should we include a Cornell-style microcontroller, or something else?
• KiCAD 5 or 6? (or conceivably Altium?)

Right now (1/18/22) there are a few Kintex-7 parts in stock at DigiKey:

• XC7K70T-1FBG484C - $207 - up to 6.6 Gbps (8 GTX transceivers)
• XC7K160T-2FBG484C - $434 - up to 10.126 Gbps (8 GTX transceivers)

See ​DS182 page 58.

Also we have a bunch of these Trenz modules: ​TE0714 which belong to Ed. They can support up to 6.25 Gbps.

Useful Links

• ​APOLLO_MECH%20Model%20(1).pdf - mechanical drawing (​DXF file)
• ​Cornell_6089-103-RevB_PCB_FAB_28Feb2019.zip - Gerber files for Cornell Rev 1 board
• ​TWEPP 2019 talk by Eric

Current Plan

• Trenz module with 4 MGT lanes
• Connect up 1 C2C lane from SM and TTC/TTS-like links
• Other Trenz links can go to an SFP+
• Possibly two sites for Trenz?
• Add Cornell MCU or possibly more simple MCU (Dan to ask Peter)
• Front panel LEDs, SFP+, USB-UART, SMAs, GPIOs?
• Only use one Power connector.
• Connect up both high speed connectors (to different Trenz sites)
• CM connector info ​link
• Add simple temperature sensors from SM (ask Dan for part number)

CM Board Design Check

To Do List

• Please put signal names on the fast signals on your J1 and J3
• Please check again the current through the LEDs. Just a couple of mA is appropriate. Also, I'd suggest to use red for the 3.3V as it has the lowest forward voltage.
• Please put a capacitor on the VR input. The data sheet specifically recommends this.
• Please remove the vias on the jumpers on e.g. J1 from pin 4-10 and 3-9. Run those traces on the front as well
• Please add "GND" on silkscreen above and below the even pin row on J5 and J6 (sketch below)
• Please increase size of all silkscreen text to at least 50 mils (pref. 60 mils)
• Please rotate all silkscreen text right side up unless there is a compelling reason for it to be rotated
• Please connect PS_RST pin (pin 3-8 on low speed connectors) to the header with pull-up.
• Please add 100 ohm R between TTC_P and TTC_N
• Please expand J7-J10 to 3 pins with GND
• Please edit silkscreen to read: Boston University EDF Apollo CM test article Rev A 2022-03 ​http://apollo-blade.info
• Please check the footprint for the ET60 connectors. For the signal pins, don't they specify 0.7mm finished hole size? Please find and paste here the relevant datasheet drawing you used.
• Please fix the relative location of the slow and fast connectors. They don't match between your layout and Charlie's. See screenshot below. (one easy way to check this is to open your top copper and Charlie's top copper in 'gerbv' and offset so the are on top of each other. All the connector pads should exactly line up.
• Please check the footprint locations against the mechanical drawing and let me know if the mechanical drawing is wrong. Charlie's gerbers are the final say, since the boards fit properly.