Pramod V. Argade

Resonance Raman evidence of chloride binding to the heme iron in myeloperoxidase

The resonance Raman spectra of ferric derivatives of myeloperoxidase at pH 8 show ligand‐dependent differences. The data are consistent with the resting enzyme and the chloride and fluoride derivatives all having 6‐coordinated high‐spin configurations. At pH 4 we find that the resting enzyme is susceptible to photodegradation from our low power incident laser beam. Chloride binding inhibits this denaturation. Our data support direct binding of chloride to the enzyme under physiological conditions.

A technique for monitoring run-time dynamics of an operating system and a microprocessor executing user applications

In this paper, we present a non-invasive and efficient technique for simulating applications complete with their operating system interaction. The technique involves booting and initiating an application on a hardware development system, capturing the entire state of the application and the microprocessor at a well defined point in execution and then simulating the application on microprocessor simulators. Extensive statistics generated from the simulators on run-time dynamics of the application, the operating system as well as the microprocessor enabled us to tune the operating system and the microprocessor architecture and implementation. The results also enabled us to optimize system level design choices by anticipating/predicting the performance of the target system. Lastly, the results were used to adjust and refocus the evolution of the architecture of both the operating system and the microprocessor.

Sizing an inverter with a precise delay: generation of complementary signals with minimal skew and pulsewidth distortion in CMOS

A general procedure to size an inverter which drives a given capacitance load and which has precise pull-up and pull-down delays is discussed. This procedure is an iterative combination of a Newton-Raphson numerical method used to size the transistors, and ADVICE simulations to extract parameters used in the delay model for the inverter. The numerical method makes it possible to satisfy the delay constraints precisely, while ADVICE simulations ensure accuracy. This device-sizing procedure is then used to determine the sizes of inverters in two paths, one consisting of two inverters and the other three, each driving an arbitrary capacitive load, such that the complementary output of the two paths has minimal skew and pulsewidth distortion irrespective of the processing variations. A fully automatic procedure to achieve this requires only four ADVICE simulations and takes about four minutes of CPU time on an AMDAHL-5870 computer. The circuit designed by this procedure also has a very small skew and pulsewidth distortion with temperature variation with V/sub DD/ variation, and with the input rise and fall-time variations. >