CMOS Microprocessor Research Articles

On-line quantification of fetal heart rate variability.

An on-line methods for quantification of fetal heart rate variability (FHRV) from fetal electrocardiography (FECG) is presented. A CMOS microprocessor system with a 2k read-only-memory and a 4k random-access-memory is constructed. The processor is connected to a commercial cardiotocograph, and it calculates the interval index (II) measuring the long-term variability and the differential index (DI) measuring the short-term variability of FHR. The accuracy of the system was tested by calculating the FHRV indices from simultaneously recorded direct FECG and abdominal FECG. The correlation between the results of these two methods was good. II and DI were calculated serially for 34 fetuses during normal pregnancies. The FHRV analysis succeeded in 80-100 percent of patients from the 20th until the 27th week of gestation and again from the 35th week until term. The method was less successful, 35-70 percent, between gestational weeks 28 and 34. On average, II and DI grew as the gestation advanced. II had a greater scatter than DI and it was considered to measure mainly the fetal arousal level. DI on the other hand was not below three after the 30th week of gestation. DI may become a new marker of fetal status also in antepartum fetal surveillance.

Small CdTe Gamma Backscatter Assay Meter

The prototype of a portable pocket-sized coal dust incombustibles meter has been developed for the U. S. Bureau of Mines safety program. Using 60-keV Am-241 gamma rays backscattered from the dust under assay, the device measures the count rate in a CdTe detector for 25 seconds and computes the fraction of incombustible material in the dust. The battery-powered meter is intended to occupy only a 330 cm3 volume, and have a battery life of 1,000 measurements. Stability and miniaturization were achieved by the use of a small CdTe solid-state gamma detector specially designed to operate on 9V, and by the incorporation of a single-chip CMOS microprocessor. The source-detector geometry has been optimized so that the meter reading is relatively insensitive to the assay material density. The technique can be used for real-time assay of many binary mixtures, and requires roughly 100 mCi of Am-241 to achieve a measurement accuracy of a few percent.

Two-chip 12-bit CMOS microprocessor

Two-chip 12-bit CMOS microprocessor

Effects of Total Dose Ionizing, Radiation on the 1802 Microprocessor

Several versions of the 1802 CMOS microprocessor were subjected to Co-60 irradiations. Total dose data is provided for production line parts from two vendors, a specially processed radiation hard lot, and one developmental SOS unit. The increase in total dose failure level from 1 x 104 to 5 x 105 rads(Si) for the specially processed Parts proves the feasibility of hardening the Si-gate LSI technology used for the 1802.

Architecture and applications of a 12-bit CMOS microprocessor

In this paper, we describe the design, interface, and architectural features of a 12-bit single-chip microprocessor, the IM6100, implemented with a silicon gate complementary MOS (SiG CMOS) process. The features of CMOS circuits for operation in difficult noise, temperature, and power environments are noted. The microprocessor recognizes the instruction set of the PDP-8/E minicomputer. It is also programmed I/O interface compatible with the PDP-8/E. A unique feature of the IM6100 is the provision for a transparent operator console. An all-CMOS processor system with 256 × 12 RAM, 1K × 12 ROM, and a programmable asynchronous serial interface port can be built with seven LSI devices. The system dissipates 60 mW at 5 V.

Radiation Testing of an 8-Bit CMOS Microprocessor

An 8-bit CMOS microprocessor has been tested in an ionizing radiation environment. Quiescent current was monitored during the irradiation and clock frequency was a test parameter. Irradiated in a static condition, failure was observed at a total dose of 3 x 10$sup 4$ rads (Si). (auth)