ARMed and Dangerous
Actel/ARM Tackle Embedded Applications
Kevin Morris, Embedded Technology Journal
October 25, 2005
The pecking order in the playground of FPGA technology has been established for awhile now. Two big boys rule the roost. Other players quietly compete in the corners for their share of the scraps. Now, however, with the FPGA players moving rapidly into the embedded systems space, that hierarchy is bound to be challenged. Actel, one of the kids playing stealthily at the edge of the FPGA schoolyard, has made a shrewd move by buddying up to ARM, one of the biggest, strongest forces in the embedded market, and it’s not likely that anybody will be kicking sand in their face any time soon.
Actel announced this week that they are now shipping versions of their previously announced ARM7-enabled, flash-based FPGAs. The Actel/ARM7 combination is a unique platform for system-on-chip implementation with the industry’s most popular 32-bit processor core. The barriers for entry into custom embedded system-on-chip technology have just been dramatically reduced, both in cost and in engineering learning-curve.
When attacking larger competitors, one generally has two viable options. The first is focus. By concentrating all your energy on a specific market segment where your larger competitor gives only mediocre attention, you can carve out a niche where your smaller company can flourish. For years, Actel has successfully maintained exactly this strategy with their Mil/Aero FPGA product lines, concentrating on meeting the special requirements of that market segment.
The second option is to flank the larger competitor by moving in another direction. Actel has also prosecuted this strategy with their ProASIC-3 Flash-based FPGA lines. While larger competitors jousted for supremacy in SRAM-based FPGAs, Actel flanked with their non-volatile, Flash-based technology. Touting live-at-powerup operation, single-chip solutions, and IP security, they positioned themselves as a superior alternative for certain programmable logic customers with a different set of priorities.
Now, with the help of their formidable ARM alliance, Actel is launching a new type of assault – the frontal attack. Every programmable logic vendor is now racing to capture a share of the emerging market for embedded systems on FPGAs. The two largest players in the programmable logic market, Xilinx and Altera, are betting on proprietary RISC processors (MicroBlaze and Nios, respectively) to win over the hearts and minds of embedded systems engineers. While Xilinx and Altera clearly have the brand name recognition in the programmable logic domain, neither MicroBlaze nor Nios carry the cache of ARM in the embedded processor market. From a brand recognition perspective then, an ARM/Actel combination should be at least as compelling for embedded designers as a MicroBlaze/Xilinx or a Nios/Altera.
Of course, brand names are far from being the only decision drivers for engineers. Cost, capability, and compatibility weigh in heavily in the system designer’s selection matrix. On the cost front, Actel and ARM have cleverly amortized the cost of the ARM core into the FPGA itself. If you buy an ARM-enabled M7 FPGA from Actel, you’ve already covered the cost of your CoreMP7 (ARM7) license. According to Actel, if you account for the amount of logic used by the ARM core, you’re getting the processor for as little as $2.75. This also means that you have no separate royalty or licensing fees with ARM, as everything is conveniently covered in the price of the part.
Capability-wise, the ARM core is a specialized soft IP core on the Actel device that can be reconfigured to meet the needs of your particular application. In the Actel FPGA, the ARM can run at speeds up to 25MHz. It is compliant with ARM7TDMI-S with 32-bit ARM and 16-bit Thumb instructions, 32-bit ALU with 3-stage pipeline, and 32-bit bus interface. If you pick one of the larger FPGAs, you’ll have lots of room left over for peripherals and custom logic, while still keeping your entire computing system on a single chip.
Concerning compatibility, the ubiquity of the ARM architecture means that loads of software already in use is fully compatible with the Actel/ARM environment, as well as a robust, proven set of development and debugging tools. Product teams with an investment in prior ARM-based projects should be able to easily adapt to the FPGA implementation with both legacy software and development flows. This means we should see Actel-based ARM implementations up and running relatively quickly since many teams will have a substantial head start on the software side.
Until this, you had to either buy an ARM-based microcontroller or take the ASIC plunge in order to include an ARM processor in your embedded system. Compared with the microcontroller option, the FPGA solution is much more flexible, and it gives the opportunity for much greater integration, as substantial amounts of user logic as well as peripherals can be included on the same chip, virtually for free. Compared with the ASIC option, the FPGA has substantially lower development costs, can be deployed at virtually any volume level, and can be modified even in the field because of its reprogrammability.
Wait… we see a hand in the back row. Yes, it’s true that this is not the first FPGA-based ARM implementation on the market. A few years ago, Altera introduced an FPGA family with a hard-core implementation of an ARM processor. This family saw limited market success, probably because of a mismatch of features and capabilities. The ARM processor was very popular in low-cost, high-volume, often low-power applications. The Altera FPGA family, however, was (at the time) a relatively high-end, expensive, power-hungry device. The matchup missed the mark for many applications, either because of the cost and power demands of the chip, or because of the lack of flexibility in the hard-core processor implementation.
Actel’s offering is a different animal, however. The ProASIC-3 family (on which the ARM-enabled technology is based) is already targeted at the price- and power-sensitive high-volume applications areas like consumer and automotive. The particular properties of the Flash-based FPGA technology such as single-chip footprint (other types of FPGAs require boot PROMs and other support circuitry), low power consumption, non-volatile, live-at-powerup operation, and IP security are important in these applications as well.
In addition to announcing the shipment of the new M7 ARM-enabled devices, Actel is announcing a host of development tools and IP for the family. The new CoreConsole IDP is a GUI-based platform configuration tool that allows a system designer to quickly stitch together a complete embedded system-on-chip, including processor, peripherals, and other IP cores as well as any SPIRIT-compliant user IP. CoreConsole allows connection of components on both AHB and APB busses as well as memory and interrupt controllers and power-on/reset blocks.
On the software development side, Actel is offering their RealView Developer’s Kit, which includes compiler, debugger, linker, instruction set simulator, and RVI-ME probe. They’re also offering a CoreMP7 Development Kit that includes a standalone development board with a 600K gate ARM-enabled FPGA, 2MB of flash, and 2MB of SRAM as well as connectors for RS232, Ethernet, USB, CAN and AHB bus. The low-cost kit helps jump-start development teams with an easy-to-configure working system where they can immediately begin running software and developing and debugging external interfaces.
The FPGA family ranges from 250K to 3 million gates of logic with up to 504kb embedded SRAM and 616 user I/O pins. The 250K, 600K and 1M gate devices (M7A3P250, M7A3PE600 and M7A3P1000) are available now, with remaining sizes scheduled over the next few months. CoreConsole is available now with a $395 annual license fee, and the RealView development kit is available with an $1195 annual license. The CoreMP7 development kit is scheduled to be available in January, 2006.
Don’t expect the Actel/ARM duo to run away with the entire embedded FPGA market, however. With the huge diversity of applications and explosive increase in demand, other companies will continue to field FPGAs with compelling advantages for many types of projects. The particular features of the Actel/ARM offering, however, with the extreme ease of implementation of an ARM-based system-on-chip, will definitely win their share of sockets. |
