Silicon Engineering has extensive experience in embedded system design, both with our own microprocessor designs as well as third party processors.

We have numerous cores and memory macrocells that allow a system on a chip to be quickly built around a processor core.

An illustrative example of an embedded system design is a chip we designed for Sensory - then a fledgling startup in the speech recognition and synthesis business. They needed a low-cost solution for the consumer market, capable of executing their proprietary neural net-based speech recognition software. The chip also needed to synthesize speech to allow spoken interaction between the user and the system.

Silicon Engineering provided a small 8-bit microprocessor, the SEMic core (see "Cores & IP") as the main system processor. We also supplied a half-megabit ROM for the internal code ROM, as well as several SRAM cores which served as processor scratchpad RAM and code and data RAMs for the digital filter unit which SEI converted from a dual FPGA prototype filter that Sensory had designed.

The chip needed to be able to "listen" and "speak", so SEI's analog designers developed an analog-to-digital converter to take direct analog microphone input and convert it to digital values that could be processed by the digital filter and processor and recognised as speech. For the output, the processor drove a pulse-width modulator unit which controlled two high-drive output pads that powered a small speaker directly.

The power requirements for the system were very stringent to allow for battery operation over a wide voltage range as the battery runs down. Several low-power and power-down modes were included to allow the processor to run at a fraction of its normal power when high-speed processing was not required, or to power down completely when not needed. The processor could be woken up from a pin interrupt or an internal low-power timer.

General-purpose IO pins were also included to allow the processor to control or sense the state of external signals on the system board. Essentially the entire system was implemented on a single small chip. The layout, verification and tape out in GDS-II format was all done by SEI.

The chip won the EDN Product of the Year award when it was introduced, and has been shipping in various forms for over two years.

SEI also has experience with other processor cores in embedded environments. These include PowerPC cores, and Intel, MIPS and ARM processors.