Browse Prior Art Database

File Adapter Checking System

IP.com Disclosure Number: IPCOM000050887D
Original Publication Date: 1982-Dec-01
Included in the Prior Art Database: 2005-Feb-10
Document File: 2 page(s) / 52K

Publishing Venue

IBM

Related People

Jones, DF: AUTHOR [+2]

Abstract

A data deserializer 10 (Fig. 1) decodes the data stream from the file adapter 50 to the file 100 to provide a signal indicating when certain bytes of data are present so as to enable error forcing into the data stream written to the disk file 100, whereby upon read back of the file adapter 50 the forced errors are detected for diagnostic purposes. The file adapter 50, in addition to serializing and deserializing data to be written to and read from the file 100, also adds certain bytes into the data stream which are used for control purposes. These added bytes (Fig. 2) include Gaps, Sync, CRC (cyclic redundancy check, ECC (error correction code) and ID (identification). It is desirable to be able to check to see if the adapter 50 added the control bytes correctly.

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File Adapter Checking System

A data deserializer 10 (Fig. 1) decodes the data stream from the file adapter 50 to the file 100 to provide a signal indicating when certain bytes of data are present so as to enable error forcing into the data stream written to the disk file 100, whereby upon read back of the file adapter 50 the forced errors are detected for diagnostic purposes. The file adapter 50, in addition to serializing and deserializing data to be written to and read from the file 100, also adds certain bytes into the data stream which are used for control purposes. These added bytes (Fig. 2) include Gaps, Sync, CRC (cyclic redundancy check, ECC (error correction code) and ID (identification). It is desirable to be able to check to see if the adapter 50 added the control bytes correctly.

The data deserializer 10 (Fig. 1) performs two of the major functions necessary to verify proper operation of file adapter 50. The first is to monitor and allow displaying the data stream between the adapter and file 100. The second is to inject single- or multi-bit errors into the data stream.

The display function operates by sensing the data stream, converting the data into bytes, and sending the byte-wide data to an external logic analyzer 20. The displayed data can then be easily compared to specification. A sample data stream that would be sent by the adapter 50 is shown in Fig. 2. The segments labeled "Generated by the File Adapter" are generated internal to the adapter and can only be seen at the interface between the adapter and file. the deserializer 10 provides the means to display this data.

The error...