Mannerisms

Fundamental patents issued to the industry pioneers which have expired are:

The Freeman patent, issued to Ross Freeman co-founder of Xilinx, covering the interconnection method used in SRAM-based FPGA, expired in 2005.

An Altera patent, issued to Robert Hartman, co-founder of Altera, which covers the fabrication of macro-cells in EPROM-based PLDs, expired in 2002.

A patent issued to Lattice Semiconductor on how to build EEPROM-based PLDs expired in 2004.

And a patent covering the use of anti-fuse technology in programmable logic devices, issued to El Gamal of Actel in 1989 expired in 2005.

To some extent the expiration of these patents may have already have had some effect as shown by the increase in FPGA start-up activity recently with companies like MathStar, Achronix, Cswitch and Velogix. (Velogix has now folded).

The established companies stress the barriers these start-ups need to overcome, pointing to the lack of third party place and route software, the prohibitive expense of developing it yourself, and the difficulty for start-ups of getting access to aggressive process technology