According to its manufacturer, the radiation-tolerant RTAX4000S FPGA offers the highest density for space designs. This Actel device provides 4 million system gates, which is roughly equivalent to about 500k ASIC gates. Furthermore, it tolerates a total ionizing dose of up to 300 krads (silicon, functional), exceeding the requirements for most space applications (see the figure).
This antifuse-based FPGA has a single-event latch-up immunity of greater than a linear energy transfer (threshold) of 104 MeV-cm2 per milligram of silicon and single-event memory upsets (SEUs) of less than 1E-10 errors per bit-day. Internal memory consists of 540 kbits of hardened SRAM with error-detection and correction, divided into 120 blocks. There are up to 840 user-configurable I/O pads on the chip as well. Internal flip-flops were designed to be practically immune to single-event upsets. The SEU-hardened devices do not require customer-initiated triplemodule redundancy since they incorporate an on-chip voting capability. Also, the antifuse FPGAs are immune to configuration upsets.
Three package options are available—a ceramic quad flat package with 352 pins, a 1272-contact ceramic column-grid array, and a 1272-contact land-grid array— depending on system I/O needs. In addition to the fully space-qualified chips, the company offers a lower-cost nonflightworthy but identical version that can be used for prototyping.
Samples of the RTAX4000S will be available in the first quarter of 2006. Software support is available now. A flash-based RHAX-S family of FPGAs fabricated on a radhard process at the BAE-Manassas facility is under development. Contact Actel for sample and production pricing.