CRUVI FPGA Card

The CRUVI FPGA Card is a daughter card standard specifically tailored to the needs of FPGAs.

Background
The expansion bus interface is designed to create an open ecosystem of function modules for high-performance peripheral connectivity. Its main focus is on supporting FPGA and FPGA SoC devices from all major manufacturers like Altera, Lattice, Microchip and Xilinx.

The word "CRUVI" is a combination of the Estonian word "KRUVI" for screw and the letter "C", which refers to the half of the hexagonal screw head. In this case, the "K" was replaced with "C" to emphasize the reference to the screw head.

Overview
It can be used to build high performance prototypes, for system integration and testing to build complex systems from smaller building blocks to iterate quickly and reduce cost. Create custom test systems for production functional testing.

The carrier module supplies the power supply, the input/output voltage and controls the functions of the peripheral modules.

The CRUVI open standard coexists between low speed, low pin-count like Pmod Interface devices and high-performance, high pin-count (HPC), 400 I/O FPGA Mezzanine Card (FMC) peripherals.

Three board-to-board connectors are specified: CRUVI-LS (Low Speed), CRUVI-HS (High Speed) and CRUVI-GT (Gigabit Transceiver) PCIe Gen 5.0 capable.

Bridging adapter exists to convert signals from Pmod to CRUVI-LS (CR00025), from FMC to CRUVI-HS (CR00101, CR00111) and FMC to CRUVI-GT (CR00112).

History of CRUVI specification
International contributors to define the open source CRUVI specification are Trenz Electronic GmbH, Arrow Electronics, Samtec, Flinders University, Synaptic Laboratories Ltd, Symbiotic EDA and MicroFPGA UG.

Structure and description of the carrier modules
Single, double or triple width modules are allowed and they have more mounting holes.

A triple size of space on carrier board is 67.72 x 57.5 mm2 (2.66535 x 2.26378 inch²). There are 3 slots. The mounting holes (1 to 6) for M2 screws are 2.2 mm (0.0866 inch) diameter and need SMD spacer for mechanically fixing. The CR99201 PCB template has LS and HS connectors named: AX, BY and CZ. The CR99500 PCB template has LS, HS and GT connectors.

Structure and description of the peripheral modules
There are different single peripheral module possible, flexible and scalable by size LS, HS and GT connectors. Mounting holes are for M2 screws 2.2 mm (0.0866 inch) diameter.

Templates for the peripheral modules
It is recommended to have EEPROM with I2C for identification of peripheral module with a specific address number.