NextCuboid
About the NextCuboid PCB
NextCuboid is an open source PCB design by mattuna15, published on GitHub under the MIT license. It is a 4-layer board measuring 214 × 142 mm, with 27 components from 8 distinct parts.
Other key parts include the MC68881FN-SOC, MC68SEC000FU20, SN74LVC8T245 and 74LVC1G125. By type, the board carries 11 capacitors, 7 ICs, 7 resistors and 1 connector.
From the project
Development of coprocessor.
Hardware-verified on an Alinx AXU3EG board (Zynq UltraScale+ ZU3EG) via the AXI4-Lite wrapper at 100 MHz bus / 50 MHz FPU, with end-to-end tests covering arithmetic, transcendental, exponential, and logarithmic operations.
Non-incremental synthesis + implementation, Vivado 2025.2, xc7a200tfbg676-1. Date: 2026-03-27. 50 MHz target clock. MC68882 mode enabled (fpuversiong => FPU68882). Includes FPSP-derived EXP 2^(J/64) decomposition with minimax degree-6 polynomial (EXPTBL 64-entry BRAM), LOG reciprocal table (avoids FP division), TWOTOX/TENTOX direct reduction, table-assisted ATAN/LOG…
Main components on the NextCuboid
NextCuboid bill of materials (BOM)
27 components, 8 distinct parts.
| Qty | Part | Footprint | Refs |
|---|---|---|---|
| 1 | MC68881FN-SOC | PLCC68-S | IC1 |
| 1 | MC68SEC000FU20 | LQFP-64_L14.0-W14.0-P0.80-LS16.0-BL | U1 |
| 4 | SN74LVC8T245 | 24_18.0mmx34.29mm_W15.24mm_Socket | U2, U3, U4, U5 |
| 1 | 74LVC1G125 | SOT-23-5 | U6 |
| 1 | Conn_01x06_Pin | PinHeader_1x06_P2.54mm_Vertical | J1 |
| 1 | QMTECH_CE15 | QMTECH_BOARD | B1 |
| 11 | 100nF | C_Disc_D5.0mm_W2.5mm_P2.50mm | C1, C2, C3, C4, C5, C6, C7, C8 +3 |
| 7 | 4.7k | R_Axial_DIN0207_L6.3mm_D2.5mm_P7.62mm_Horizontal | R1, R2, R3, R4, R5, R6, R7 |
NextCuboid design files
The KiCad project lives in the mattuna15/68881-fpga repository on GitHub; these links point at the commit this page was built from.
NextCuboid: common questions
How big is the NextCuboid PCB?
The NextCuboid measures 214 × 142 mm, has 4 copper layers and is 1.6 mm thick.
How many components are on the NextCuboid?
27 components, from 8 distinct parts. The full bill of materials is listed on this page.
Where can I download the NextCuboid design files?
From the mattuna15/68881-fpga repository on GitHub, which has the KiCad layout and the schematic; the links under Design files point to each one.
Can I use the NextCuboid design in my own project?
Yes, under the terms of its MIT license, which mattuna15 chose for the repository.
