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:
May. 26, 1998
Filed:
May. 12, 1994
David B Townsley, Cupertino, CA (US);
Andrew Gong, Cupertino, CA (US);
Apple Computer, Inc., Cupertino, CA (US);
Abstract
A master agent and a slave agent are interconnected over a two-conductor bus system. One conductor is utilized to transfer data signals between the agents and the second conductor is utilized to transfer a clock signal between the agents. The master agent includes a single data port for both input and output. The slave agent includes two data ports: an input port and an output port. The input port and the output port are coupled to a single conductor, thereby allowing data to be input to and output from the slave agent on a single line. An open collector device is situated between the output port of the slave agent and the data conductor. Data is transferred between the master and slave agents by first synchronizing the agents. The agents are synchronized by first allowing the data conductor to obtain a high state. Upon sensing the data conductor high, the master agent drives the clock conductor to a low state. The slave agent responds by driving the data conductor low if the agent is ready for a transfer. The master agent then drives the clock conductor high in response to the slave agent driving the data conductor low. The slave agent then drives the data conductor high, and prepares for the data transfer.