Sherman IC

Sherman IC
Name	Sherman IC
Type	Integrated Circuit
Developer	Sherman Laboratories
First release	1978
Architecture	Custom MOS
Process	3 µm
Applications	Aerospace, Telecommunications, Computing
Predecessor	S-LINE 100
Successor	Sherman IC-II

Sherman IC The Sherman IC is a historically significant integrated circuit developed by Sherman Laboratories in the late 1970s that influenced subsequent microprocessor and digital signal processor designs. It combined custom metal–oxide–semiconductor fabrication with architectural innovations that found use in aerospace avionics, telecommunications switching, and early personal computer peripherals. The design bridged several contemporaneous projects led by firms and institutions such as Intel, Texas Instruments, Fairchild Semiconductor, and research groups at MIT.

Overview

The Sherman IC was a monolithic MOSFET-based chip built using a 3 µm planar process pioneered by fabrication centers at Sandia National Laboratories and commercial fabs like National Semiconductor. Its feature set emphasized low-power consumption, deterministic timing, and on-chip register file resources, drawing conceptual lineage from designs at Bell Labs and Hewlett-Packard. The chip targeted embedded applications in platforms developed by companies such as Boeing, Raytheon, AT&T, and academic projects at Stanford University.

History and Development

The Sherman IC project began as an internal initiative at Sherman Laboratories in 1976, motivated by competition with products from Intel 8080, Motorola 6800, and prototypes from Zilog. Early funding and prototyping involved collaborations with national programs at DARPA and industrial partners including Western Digital and RCA Corporation. Design milestones included an initial tape-out in 1978, field deployments in 1979, and iterative revisions influenced by standards emerging from JEDEC and process improvements at Bell Labs Microelectronics Center.

Key contributors included engineers who previously worked on the PDP-11 family, researchers from Carnegie Mellon University, and consultants from Xerox PARC. The Sherman IC's rollout coincided with major industry events like the launch of the IBM Personal Computer and the growing adoption of microcontrollers by firms such as Siemens and NEC.

Design and Architecture

Architecturally, the Sherman IC combined a reduced-instruction-set influence with elements borrowed from contemporaneous complex-instruction designs; it implemented a compact control unit, a multi-ported on-chip register file, and a small arithmetic logic unit inspired by circuits in DEC minicomputers. The chip's instruction encoding and microcode were shaped by research from University of California, Berkeley and ETH Zurich.

On the physical side, the Sherman IC used planar CMOS techniques with polysilicon gates and a triple-metal routing scheme similar to those used at Intel fabs. Clock distribution borrowed methodologies from Xilinx FPGA clocking studies and academic work at Caltech. Peripheral integration—timers, serial interfaces, and analog-to-digital converters—reflected designs seen in products from Analog Devices and Maxim Integrated.

Variants and Models

Several variants expanded Sherman Laboratories’ product line. The Sherman IC-A focused on radiation-hardened operation for satellites and referenced testing standards from NASA and ESA. The Sherman IC-B was optimized for telecommunications switching equipment used by British Telecom and Deutsche Telekom; it added on-chip buffering and low-jitter timing compatible with systems from Siemens and Alcatel-Lucent. A low-power Sherman IC-L targeted handheld instrumentation used by Fluke and military contractors related to Northrop Grumman.

Custom versions were contracted for companies such as General Dynamics and Honeywell for avionics suites in aircraft by Lockheed Martin and McDonnell Douglas. Experimental fused-silicon iterations explored deep-submicron scaling with partners at I.B.M. Research and European fabs affiliated with STMicroelectronics.

Performance and Applications

In benchmarks and field tests, Sherman IC variants exhibited deterministic cycle timing suitable for real-time control in systems developed by NASA Jet Propulsion Laboratory and industrial control equipment from Emerson Electric. Its DSP-like instructions and multiply-accumulate paths made it suitable for signal processing tasks in Motorola-class radio equipment and early cellular network base stations by firms like Ericsson.

Power efficiency and radiation tolerance enabled use in satellite payload controllers on missions managed by NOAA and scientific instruments deployed by CERN research groups. In computing, Sherman IC-based peripheral controllers interfaced with microcomputers running operating systems influenced by UNIX and CP/M-era software stacks.

Manufacturing and Commercialization

Sherman Laboratories leveraged contract fabs and foundry agreements similar to later arrangements by companies like AMD. Early production runs were manufactured in partnership with fabs associated with Western Electric and small-scale production at facilities linked to Fairchild Semiconductor. Commercialization targeted niche markets in defense procurement and industrial instrumentation; sales channels included systems integrators such as Sperry Corporation and distributors in Silicon Valley.

Licensing agreements permitted derivatives by foreign partners in Japan and Europe, echoing patterns seen with NEC and Siemens collaborations. Marketing emphasized reliability testing protocols from MIL-STD-883 and quality certifications comparable to ISO 9001 for aerospace suppliers.

Legacy and Impact

The Sherman IC influenced later microcontroller and DSP families produced by Texas Instruments, Analog Devices, and emerging fabless firms such as Xilinx and Broadcom. Its architectural choices informed curricula at MIT and Stanford University and inspired academic papers presented at conferences like IEEE International Solid-State Circuits Conference and ACM SIGARCH.

Surviving Sherman IC devices are preserved in technical archives at institutions such as Smithsonian Institution and university collections at California Institute of Technology. Its design lineage can be traced to modern embedded subsystems in products by Apple, Qualcomm, and Intel through shared techniques in low-power design, on-chip integration, and radiation-hardened variants.

Category:Integrated circuits