MS-8

The MS-8 is a single-chip microinstrument: a mixed-signal microcontroller with a full analog front end--including voltage, current, and capacitive sensor interfaces; signal amplification; and analog to digital conversion circuitry. The only sensor integrated on this chip is for temperature, but other sensors and actuators could be included. For many applications, though, in which the MEMS devices cannot be made with CMOS process steps or in which sensor lifetime is limited, the most efficient system partitioning allocates all or most of the electronics on a microinstrument chip separate from the sensor.

The MS-8 is optimized, from instruction set definition to analog functionality, to economically support embedded sensor applications. A minimal version of the microinstrument can be implemented with as few as eight pins. The instruction set provides excellent code density and supports the ANSI C programming language. To aid code debugging, the MS-8 includes hardware support for a single breakpoint and trace event, and a development system interface provides instructions for halting the processor, single stepping through code, and reading and writing system registers. Single cycle interrupt response and direct-memory access (DMA) capabilities facilitate usage of the MS-8 in time-critical applications, and a 16 x 16 hardware multiply, 40-bit accumulate block provides significant signal processing capability for a small microcontroller. To minimize power dissipation, data paths were limited to 8-bit widths, and the chip was designed to operate on a 3-V supply, in a 0.35 um CMOS process. In addition, a clock manager provides programmability of the clock frequency for the digital and analog circuits, and each analog block can be individually powered down under software control.

If you would like to learn more about the MS-8, please contact Matt Guthaus (mguthaus@eecs.umich.edu).