Market research reports show that 10% or more of all FPGAs are used by military and aerospace systems. Clearly FPGA provides major advantages in the flexibility to adapt to changing standards and mission-critical requirements, which is essential for systems that may be in design for years and deployed for a decade or more. However, FPGA chips suffer some significant shortcomings, particularly for aerospace/defense applications. For example:
The vast majority are manufactured outside of the United States
None are manufactured in Trusted Fabs
None are truly Rad Hard
Fortunately, a technology has emerged to solve these problems: embedded FPGA. A handful of companies have successfully developed embedded FPGA IP that allows RTL to be updated at any time during the chip design process, even in system. This innovative new technology integrates FPGA into an SoC, which allows power to be reduced (by eliminating SERDES/PHYs that draw most of the power) and eliminates the packaging to enable smaller and lighter solutions.
|A comparison of a typical FPGA (left) to an embedded FPGA (right). Image source: Geoff Tate.|
Traditional FPGAs have been widely used in systems since the 1980s and, at the system level, provided flexibility and programmability different from what processors could do. The time has now come for this technology to be integrated -- similar to what ARM did with processor chips in the 80s. Back then, ARM took the idea of a processor chip and offered a processor architecture, which could be embedded in chips. Although it took time, embedded processors soon became nearly ubiquitous.
The same market transition is now taking place with embedded FPGA technology, providing chip designers with an option to improve the reliability, power, and size of their systems. While this technology is expected to become mainstream in many markets, the first customer to announce that it would use it was DARPA. When DARPA announced a license for all government performers earlier this year, that put embedded FPGA technology on the fast track to becoming a widely used building block in government ICs.
What is Embedded FPGA?
Traditional FPGAs combines an array of programmable/reconfigurable logic blocks in a programmable interconnect fabric. In an FPGA chip, the outer rim of the chip consists of a combination of GPIO, SERDES, and specialized PHYs such as DDR3/4. In advanced FPGAs, the I/O ring is roughly 1/4 of the chip and the “fabric” is roughly 3/4 of the chip. The “fabric” itself is mostly interconnect in today’s FPGA chips where 20-25 percent of the fabric area is programmable logic and 75-80 percent is programmable interconnect.
In contrast, an embedded FPGA IP block is just the “fabric” now integrated into any IC. Furthermore, an embedded FPGA connects to the rest of the chip using standard digital signaling, enabling very wide, very fast on-chip interconnects.
How Can Embedded FPGA Be Used?
Because of its advantages, embedded FPGA is gaining significant traction in the military and defense markets. But there are a wide range of applications ideal for embedded FPGA, from very large networking chips down to small MCU/IoT chips. If you look at 40