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. 08, 2007
Filed:
Dec. 05, 2002
Takashige Baba, Kodaira, JP;
Tatsuya Saito, Kunitachi, JP;
Hiroki Yamashita, Hachioji, JP;
Yusuke Takeuchi, Hachioji, JP;
Satoru Isomura, Hamura, JP;
Takashige Baba, Kodaira, JP;
Tatsuya Saito, Kunitachi, JP;
Hiroki Yamashita, Hachioji, JP;
Yusuke Takeuchi, Hachioji, JP;
Satoru Isomura, Hamura, JP;
Renesas Technology Corporation, Tokyo, JP;
Abstract
A signal transmit-receive device of the invention reduces the number of high-speed signal lines required for connecting a transmitting circuit group and a receiving circuit group, and for running a loopback test on a signal transmit-receive device. The loopback test circuit uses an error detecting circuit, a test signal producing circuit, and a wiring for transmitting error information. The error detecting circuit compares a test signal pattern defined in advance by a first communication device and a received signal pattern. The test signal producing circuit produces the test signal pattern based on error information. If an error is detected, the error signal is transmitted to the test signal producing circuit through the wiring. The test signal producing circuit produces a predetermined test signal pattern if the error signal DE has an L level; upon receiving H level, it sends back the predetermined test signal pattern to the first communication device.