Fusion Family of Mixed Signal FPGAs
Instant On
Flash-based Fusion devices are Level 0 Instant On. Instant On Fusion devices greatly simplify total
system design and reduce total system cost by eliminating the need for CPLDs. The Fusion Instant On
clocking (PLLs) replaces off-chip clocking resources. The Fusion mix of Instant On clocking and analog
resources makes these devices an excellent choice for both system supervisor and system management
functions. Instant On from a single 3.3 V source enables Fusion devices to initiate, control, and monitor
multiple voltage supplies while also providing system clocks. In addition, glitches and brownouts in
system power will not corrupt the Fusion device flash configuration. Unlike SRAM-based FPGAs, the
device will not have to be reloaded when system power is restored. This enables reduction or complete
removal of expensive voltage monitor and brownout detection devices from the PCB design. Flash-
based Fusion devices simplify total system design and reduce cost and design risk, while increasing
system reliability.
Firm Errors
Firm errors occur most commonly when high-energy neutrons, generated in the upper atmosphere, strike
a configuration cell of an SRAM FPGA. The energy of the collision can change the state of the
configuration cell and thus change the logic, routing, or I/O behavior in an unpredictable way. Another
source of radiation-induced firm errors is alpha particles. For an alpha to cause a soft or firm error, its
source must be in very close proximity to the affected circuit. The alpha source must be in the package
molding compound or in the die itself. While low-alpha molding compounds are being used increasingly,
this helps reduce but does not entirely eliminate alpha-induced firm errors.
Firm errors are impossible to prevent in SRAM FPGAs. The consequence of this type of error can be a
complete system failure. Firm errors do not occur in Fusion flash-based FPGAs. Once it is programmed,
the flash cell configuration element of Fusion FPGAs cannot be altered by high-energy neutrons and is
therefore immune to errors from them.
Recoverable (or soft) errors occur in the user data SRAMs of all FPGA devices. These can easily be
mitigated by using error detection and correction (EDAC) circuitry built into the FPGA fabric.
Low Power
Flash-based Fusion devices exhibit power characteristics similar to those of an ASIC, making them an
ideal choice for power-sensitive applications. With Fusion devices, there is no power-on current surge
and no high current transition, both of which occur on many FPGAs.
Fusion devices also have low dynamic power consumption and support both low power standby mode
and very low power sleep mode, offering further power savings.
Advanced Flash Technology
The Fusion family offers many benefits, including nonvolatility and reprogrammability through an
advanced flash-based, 130-nm LVCMOS process with seven layers of metal. Standard CMOS design
techniques are used to implement logic and control functions. The combination of fine granularity,
enhanced flexible routing resources, and abundant flash switches allows very high logic utilization (much
higher than competing SRAM technologies) without compromising device routability or performance.
Logic functions within the device are interconnected through a four-level routing hierarchy.
Advanced Architecture
The proprietary Fusion architecture provides granularity comparable to standard-cell ASICs. The Fusion
device consists of several distinct and programmable architectural features, including the following
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Embedded memories
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Flash memory blocks
FlashROM
SRAM and FIFO
PLL and CCC
Clocking resources
Revision 4
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