Designing the Cube

Facts

64 FPGA on board
50 Capacitors per FPGA (3,276 caps on board)
over 120 connections per FPGA (over 39,000 on board)

Speed

Target internal speed: 200MHz
Target I/O speed: 100MHz

Power

One TI PTH05030W power module per row providing 30A max. current at 1.2V for VCCINT.
Dual ATX power connectors on board.
Separated VCCINT power plane for each row.

PCB

Total 8 layers:
Top: component and routing
layer 2: VCCAUX
layer 3: VCCIO
layer 4: internal routing
layer 5: internal routing
layer 6: GND
layer 7: VCCINT, +5V, VCC1.8
Bottom: component and routing

Fall safe

Each FPGA can be programmed individually through jumper at the programing lines.
Each FPGA can access a 32 bits GPIO header for debugging.
Every two rows can be skipped through jumper setting in case any of the FPGAs on these rows failed.