Browse Prior Art Database

A METHOD FOR CONTINUOUS DUTY-CYCLE MEASUREMENT

IP.com Disclosure Number: IPCOM000014230D
Original Publication Date: 1999-Dec-01
Included in the Prior Art Database: 2003-Jun-19
Document File: 2 page(s) / 28K

Publishing Venue

IBM

Related People

Bob Faust: AUTHOR [+4]

Abstract

Microcontrollers are self-contained computer chips that can read external signals and states, and transmit commands and information. They are embedded in devices large and small for the purpose of human interface, data gathering, and automatic control. Reading, processing, and displaying state or status information is one of many important roles for embedded controllers, as they are called. Embedded controllers are usually very limited in the amount of on-board random access memory (ram) they contain. Ram is the memory used for variable and computational data. A PROBLEM An embedded controller application continuously sampled a number of signal lines to determine the percentage of time each line was active. Another name for this time percentage is "duty-cycle".

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A METHOD FOR CONTINUOUS DUTY-CYCLE MEASUREMENT

Microcontrollers are self-contained computer chips that can read external
signals and states, and transmit commands and information. They are
embedded in devices large and small for the purpose of human interface, data
gathering, and automatic control. Reading, processing, and displaying state
or status information is one of many important roles for embedded controllers,
as they are called.

Embedded controllers are usually very limited in
the amount of on-board random access memory (ram)
they contain. Ram is the memory used for variable
and computational data.

A PROBLEM

An embedded controller application continuously
sampled a number of signal lines to determine the
percentage of time each line was active. Another
name for this time percentage is "duty-cycle".

The method used, was to take ten groups of samples,
then calculate a duty-cycle average for each signal
line in each of the ten groups. The average
duty-cycle for each line was then displayed on an
operator panel. The oldest group of samples was
then over-written by new samples and the process
repeated. This method of averaging is called a
"rolling average".

A problem resulted when the number of signal lines
was increased. The embedded controller lacked
sufficient ram for ten groups of variables to hold
samples for the expanded number of signal lines.

A SOLUTION

A method of continuous integration was devised to
replace the rolling average method.

1. Only two sample arrays (groups) were required...