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Channel WRAP Test Method and Apparatus

IP.com Disclosure Number: IPCOM000035661D
Original Publication Date: 1989-Jul-01
Included in the Prior Art Database: 2005-Jan-28
Document File: 3 page(s) / 118K

Publishing Venue

IBM

Related People

De Azevedo, JB: AUTHOR [+2]

Abstract

A method for testing parallel channel hardware by transferring data between two channels, without using I/O devices, is described in the following. (Image Omitted)

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Channel WRAP Test Method and Apparatus

A method for testing parallel channel hardware by transferring data between two channels, without using I/O devices, is described in the following.

(Image Omitted)

During the test two channels are connected via a special wrap cable and a data transfer is then executed. One of the channels is in NORMAL mode and receives the data (IN operation); the other channel is in WRAP mode and sends the data (OUT operation) at the speed determined by an external oscillator. The data transfer is executed in data streaming mode.

Fig. 1 shows the connection between the two channels for the wrap test. Note that DATIN and SRVIN for the wrap channel are generated by an external oscillator with a 280 ns pulse width and 50% duty cycle; these signals are not dependent on the DATOUT/SRVOUT sent by the normal channel.

For the following discussion please refer to Figs. 2 and 3. After the initial selection sequence is executed, both the normal and the wrap channel wait for a DATIN or SRVIN that would be sent by the Control Unit in order to initiate the data transfer. The DATIN/SRVIN for the wrap channel are generated by an external oscillator. As soon as the wrap channel goes to Data Mode, data is transferred from the Channel Data Buffer (CDB) to its internal 8-byte data register, activating signal DATAVL as the first byte is loaded into a data register. The DATAVL signal must be active as long as the wrap channel is in Data Mode. This will always be...