The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Oct. 28, 1997
Filed:
Apr. 13, 1995
Sani El-Fishawy, Santa Clara, CA (US);
Andrew J Read, Sunnyvale, CA (US);
L Curtis Widdoes, Los Altos, CA (US);
Robert Mardjuki, Danville, CA (US);
Synopsys, Inc., Mountain View, CA (US);
Abstract
The present invention describes a novel method and apparatus for sampling an input/output pin of an electronic device at high speeds, comprising the steps of: driving the device input/output pin through a series resistor with a middle voltage between the high and low voltages of the device; sampling and latching the voltage at the input/output pin; comparing the latched voltage at the device input/output pin with a high threshold voltage which is between the high voltage of the device and the middle voltage; comparing the latched voltage at the device input/output pin with a low threshold voltage which is between the low voltage of the device and the middle voltage; and using the results of the two comparisons to determine whether the device input/output pin is driving high, driving low, or in an input mode.