VLSI design of a robotic controller for a dual axis manipulator element

The overall architecture of the dual-axis manipulator element and its importance as a fundamental building block of an advanced telerobotic system are described. The design, implementation, and testing of a custom VLSI chip that provides multiaxis sensor interfacing and signal conditioning are discussed. The current chip design includes: two quadrature phase optical decoders with a 16-bit resolution, three pulse-width-modulated waveform generators with 11-bit precision, and a digital input/output microprocessor interface. Each of these components have been laid out with VLSI CAD (computer-aided design) tools and have been extensively computer simulated. A 64-pin prototype chip has been fabricated in 3-μm SCMOS technology with an expected clock rate of 10 MHz for the pulse-width modulated waveform generators and 8 MHz for the optical decoders. The custom chip replaces over 125 standard SSI/MSI CMOS and TTL services and achieves a bit resolution far greater than what is currently available with off-the-shelf components