Actel brings ARM M3 to all-in-one FPGA
Actel has launched a new version of its Fusion family, which combine programmable analogue functions with digital logic, that includes a hardwired ARM Cortex-M3 processor.
Previous versions of Fusion could include a stripped-down Cortex core, the M1, but these were implemented using programmable logic. The SmartFusion launched today at the Embedded World show in Nürnberg provides a faster processor, running at up to 100MHz, and more space for user logic.
“What makes it possible is the flash technology that we have,” said Fares Mubarak, senior vice president of marketing and engineering at Actel. “Conventional CMOS is no good because you need high-voltage analogue support.”
Actel takes advantage of the 130nm Infineon embedded-flash process that it uses, which needs high-voltage transistors to program the memory cells, to implement the analogue circuits. Like its predecessor, the SmartFusion uses the ProASIC3 flash-based FPGA technology that Actel has had fabbed at Infineon for a number of years.
The analogue section is not fully programmable. Instead, it supports a number of analogue circuits that can be configured to support different functions, such as A/D conversion.
“The biggest innovation we have is what we call the analogue compute engine,” said Mubarak. “ACE has its own 8bit microcontroller that manages all the sequencing, initialisation and pre- and post-processing of the analogue signals. It doesn’t burden the FPGA with that, which is expensive, or burden the M3 with taking interrupts. In fact, you have a multiprocessor system here.”
The FPGA section can also be programmed while the processor is running using a built-in state machine. “The in-application programming controller allows the microcontroller to get into a mode where it can reprogram the FPGA while the chip is powered up and continues to control the system,” said Mubarak.
Mubarak said motor control is one target application for the SmartFusion device.
“Motor control is a perfect example of hardware-software codesign. You can implement closed-loop torque control, power and flux management in FPGA gates,” he explained, as these have very high update rates. “And perform speed control, position interpolation and network interfacing on the microcontroller.”
Mubarak refused to provide any information on pricing for the SmartFusion, but claimed: “We are selling this against designs that need an FPGA. We won’t make you pay a premium for that. It will be single digit in high enough volumes.”