Microcontroller with Memory for Extreme Temperature Applications

Authors: H. M. Soo, C. Hutchens, C. M. Liu, Z. Yuan, S. Velore, J. Gaisler, M. Willett, and V. Madhuravasal

Venue: International Conference on High Temperature Electronics (HiTEC 2008), Albuquerque, New Mexico, May 12-15, 2008 (http://www.imaps.org/hitec/exhibitinfo08.htm)

Abstract: A 68HC11 microcontroller, a LEON3 processor (code by Gaisler Research), and 4k-SRAM and 2k-ROM with the SPI interface are designed, constructed and tested by MSVLSI design group of Oklahoma State University for extreme temperature applications.

68HC11 microcomputer chip (operating in 275^oC at 3 MHz) consists of the microprocessor, ALU, a small boot ROM (512 bytes), 4 kbyte data RAM, counter/timer unit, serial peripheral interface (SPI), asynchronous serial interface (SCI), and the A, B, C, and D parallel ports. The internal Boot ROM triggers CPU to load programs over SPI or SCI into the internal RAM, and it also contains self-test code that help in peripherals and memory diagnostic for proper functionality. The high temperature version of the LEON3 is configured with 1K instruction cache, 1K data cache (SRAM) with tag, 32x32 register file, JTAG, generic APB UART, CAN controller, interrupt controller, timer, LEON3 memory controller, AHB/APB bridge, LEON3 debug support unit, general input/output ports, and can-driver. The LEON3 test results have demonstrated full functionality operating at 18MHz in 200^oC environments. The 68HC11 and LEON3 microcontrollers were placed and routed using OSU MSVLSI group’s extreme temperature cell library.

The SPI SRAM and SPI ROM test results demonstrated good yield functioning from 2 MHz to 8MHz across the temperature of 27°C to 295°C.

The 68HC11 and LEON3 microcontrollers, SPI 4k-SRAM and 2k-ROM were fabricated on the Peregrine 0.5um SOS process, tested on wafer for functionality, timing and temperature tolerance, all demonstrated suitable for control and data acquisition across the extreme temperature.

Related NETL Project:
This presentation is related to the NETL project DE-FC26-05NT42656, “Design of a 275^oC Downhole Microcomputer System Integrated Circuit.” The objective of this project is to produce a downhole microcomputer system (DMS) capable of operating at 275^oC for 1000 hours. The base DMS will consist of a 68HC11 microprocessor with an external read-only-memory (ROM) that will hold instructions for the DMS and an external random-access-memory (RAM) that will be able to store data or other bits of information. This DMS is an important high temperature (HT) electronic component needed for deep, downhole applications in wire line conveyed tools, downhole motors and other potential "smart" equipment designed for application in HT downhole environments. This DMS will also work in conjunction with other HT electronic components under development.

NETL Project Contacts
NETL – Virginia (Ginny) Weyland (Virginia.WEYLAND@netl.doe.gov or 918-699-2041
Oklahoma State University – Chriswell G. Hutchens (hutchen@ceat.okstate.edu or 405 744-5168