Browse Prior Art Database

Micro Controller Program for Pseudo Random Electrostatic Discharge Pulse Generator

IP.com Disclosure Number: IPCOM000114717D
Original Publication Date: 1995-Jan-01
Included in the Prior Art Database: 2005-Mar-29
Document File: 4 page(s) / 152K

Publishing Venue

IBM

Related People

Bou-Ghannam, A: AUTHOR [+7]

Abstract

Disclosed is a method which solves the implementation problem of using an 8-bit micro controller as a pseudo random Electrostatic Discharge (ESD) pulse generator.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 47% of the total text.

Micro Controller Program for Pseudo Random Electrostatic Discharge
Pulse Generator

      Disclosed is a method which solves the implementation problem
of using an 8-bit micro controller as a pseudo random Electrostatic
Discharge (ESD) pulse generator.

      ESD can cause a number of problems with any kind of electronic
system.  Computer circuitry is particularly sensitive to ESD.  ESD
can come from a number of natural sources including people,
furniture, blowing air, and other equipment.  To test a piece of
equipment's susceptibility to ESD, IBM* and other companies will
expose the equipment to increasingly higher voltages of ESD while the
machine, computer, etc., is running.  This invention disclosure
describes a program that implements a pseudo random ESD pulse
generator on an 8-bit micro controller.  This results in a more
portable and lower cost design than described in (*).

      This program is written in a combination of BASIC52 language,
for ease of programming, and 8052 assembly language, to satisfy a
necessary speed requirement.  The program starts by initializing 2
timers (1) for later use in generating pseudo random time delays.
The program prompts an operator to first select either "random"
testing or "deterministic" testing (not shown) using the display and
keypad of the micro controller.  If "random" testing was selected
(2), the operator would be prompted to enter the "cycle time" (3) of
the machine under test.  Cycle time is defined as the time it takes
the machine under test to execute one step or subprocedure of a
program.  Next the operator will be prompted to enter the "test
program length" (4).  The "test program length" is defined as the
time it takes the machine under test to execute all of the
instructions of the test program.  Next the operator would be
prompted to enter the "proportion" (5).  The "proportion" is the
percentage of the instructions in the test program that you wish to
have receive an ESD discharge.  The tester will then calculate and
display "number of steps" (6) of the test program = "test program
length"/"cycle time".  Also, the "number of steps tested" (7) =
"proportion" * "test program length"/"cycle time".  Next the operator
will be prompted to enter the "minimum fire time" (8).  The "minimum
fire time" is the shortest period of a random on/off cycle.  The
maximum period will automatically be set at twice the minimum period.
The firing time will vary randomly between these upper and lower
values.  The "average firing time" (9) will then be calculated and
displayed.  The "average firing time" will be halfway between the
minimum and maximum firing times because of the random distribution
of the "firing time".  Next the operator may select to either specify
the "length of the ESD test" (10) or a "probability of coverage" of
the test program.  If "length of ESD test" is selected then the
operator inputs the length of time (11).  The ESD tester will then
calculate...