Browse Prior Art Database

Wrap Capability for Synchronous Transmission Mode

IP.com Disclosure Number: IPCOM000060520D
Original Publication Date: 1986-Apr-01
Included in the Prior Art Database: 2005-Mar-08
Document File: 2 page(s) / 34K

Publishing Venue

IBM

Related People

Poiraud, C: AUTHOR

Abstract

The device shown in the drawing allows wrap tests to be performed for checking the synchronous link connecting a communication controller to a modem to resolve the field replaceable unit isolation problem when a default occurs on the link. In case of a synchronous link between the communication controller and a modem, the data exchanges are performed under control of clock signals provided by the modem and referenced by "Transmit clock" and " Receive clock". When the modem is disconnected from the link, the clock signals do not exist any more and the synchronous link cannot be tested by a wrap block. In that case, a clock signal is sent under control of a command activated by the test program.

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Wrap Capability for Synchronous Transmission Mode

The device shown in the drawing allows wrap tests to be performed for checking the synchronous link connecting a communication controller to a modem to resolve the field replaceable unit isolation problem when a default occurs on the link. In case of a synchronous link between the communication controller and a modem, the data exchanges are performed under control of clock signals provided by the modem and referenced by "Transmit clock" and " Receive clock". When the modem is disconnected from the link, the clock signals do not exist any more and the synchronous link cannot be tested by a wrap block. In that case, a clock signal is sent under control of a command activated by the test program. In operation, the control register bit A is set to 0 and the signal NEW SYNC is normally selected at the output of the AND-OR circuit and sent to the modem via the driver. In wrap test mode, the control register bit A is set to 1 and the clock signal at 1280 Hz is sent instead of NEW SYNC. The wrap block connected at the link end causes the clock to be wrapped on the Transmit and Receive clock lines.

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