Cube Architecture

The Stream Line

In the Cube project, each FPGA is connected to it's left and right neighbors only. Thus 64 FPGA on a board will form a 64 nodes chain which can be extended to 512 nodes with 8 boards installed. Eight FPGAs are grouped into a row and there are eight rows on a board. 64-bit data bus and 8 bit address/control bus are provide in the chain.

The FPGA

Xilinx Spartan 3 FPGAs (XC3S4000-FG676) are used in this project. Each Spartan FPGA has 4 Million system gates (62,208 equivalent logic cells).

The Configuration

The FPGA can be configured using either Slave-Serial Mode or JTAG mode. In the Slave-Serial mode, each row of FPGA is programmed by a Xilinx CoolRunner-II CPLD.