InfoMagic Standards 1993 July

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.fo Section 7 # 7. Command Descriptions for All Device Types 7.1 Group 0 Commands for All Device Types. These commands shall be as listed in Table 7-1. Table 7-1 Group 0 Common Commands for All Device Types ============================================================================== Operation Code Type Command Name Section ------------------------------------------------------------------------------ 00H O TEST UNIT READY 7.1.1 01H * 02H V 03H M REQUEST SENSE 7.1.2 04H * 05H * 06H V 07H * 08H * 09H V 0AH * 0BH * 0CH V 0DH V 0EH V 0FH * 10H * 11H * 12H E INQUIRY 7.1.3 13H * 14H * 15H * 16H * 17H * 18H O COPY 7.1.4 19H * 1AH * 1BH * 1CH O RECEIVE DIAGNOSTIC RESULTS 7.1.5 1DH O SEND DIAGNOSTIC 7.1.6 1EH * 1FH R ============================================================================== Key: M = Command implementation is mandatory. E = Command implementation is required for SCSI devices that support device-independent self-configuring software. O = Command implementation is optional. R = Operation code is reserved for future standardization. V = Operation code is available for vendor unique commands. * = These operation codes may have different meanings for specific types of peripheral devices. (See the appropriate section for further information.) .pa 7.1.1 TEST UNIT READY Command Peripheral Device Type: All Operation Code Type: Optional Operation Code: 00H Table 7-2 TEST UNIT READY Command ============================================================================== Bit| 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | Byte | | | | | | | | | ============================================================================== 0 | Operation Code | -----|-----------------------------------------------------------------------| 1 | Logical Unit Number | Reserved | -----|-----------------------------------------------------------------------| 2 | Reserved | -----|-----------------------------------------------------------------------| 3 | Reserved | -----|-----------------------------------------------------------------------| 4 | Reserved | -----|-----------------------------------------------------------------------| 5 | Vendor Unique | Reserved | Flag | Link | ============================================================================== The TEST UNIT READY command (Table 7-2) provides a means to check if the logical unit is ready. This is not a request for a self test. If the logical unit would accept an appropriate medium-access command without returning CHECK CONDITION status, this command shall return a GOOD status. 7.1.2 REQUEST SENSE Command Peripheral Device Type: All Operation Code Type: Mandatory Operation Code: 03H Table 7-3 REQUEST SENSE Command ============================================================================== Bit| 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | Byte | | | | | | | | | ============================================================================== 0 | Operation Code | -----|-----------------------------------------------------------------------| 1 | Logical Unit Number | Reserved | -----|-----------------------------------------------------------------------| 2 | Reserved | -----|-----------------------------------------------------------------------| 3 | Reserved | -----|-----------------------------------------------------------------------| 4 | Allocation Length | -----|-----------------------------------------------------------------------| 5 | Vendor Unique | Reserved | Flag | Link | ============================================================================== The REQUEST SENSE command (Table 7-3) requests that the target transfer sense data to the initiator. The sense data shall be valid for a CHECK CONDITION status returned on the prior command. This sense data shall be preserved by the target for the initiator until retrieved by the REQUEST SENSE command or until the receipt of any other command for the same logical unit from the initiator that issued the command resulting in the CHECK CONDITION status. Sense data shall be cleared upon receipt of any subsequent command to the logical unit from the initiator receiving the CHECK CONDITION status. In the case of the single initiator option (see 5.1.3.4), the target shall assume that the REQUEST SENSE command is from the same initiator. The allocation length specifies the number of bytes that the initiator has allocated for returned sense data. An allocation length of zero indicates that four bytes of sense data shall be transferred. Any other value indicates the maximum number of bytes that shall be transferred. The target shall terminate the DATA IN phase when allocation length bytes have been transferred or when all available sense data have been transferred to the initiator, whichever is less. The REQUEST SENSE command shall return the CHECK CONDITION status only to report fatal errors for the REQUEST SENSE command. For example: (1) The target receives a nonzero reserved bit in the command descriptor block. (2) An unrecovered parity error occurs on the DATA BUS. (3) A target malfunction prevents return of the sense data. If any nonfatal error occurs during the execution of the REQUEST SENSE command, the target shall return the sense data with GOOD status. Following a fatal error on a REQUEST SENSE command, sense data may be invalid. A target may implement the nonextended, the extended, or both sense data formats. (Implementors note: Targets that implement both sense data formats may select the nonextended sense data format in response to an allocation length of zero. Other methods of selection are also feasible.) 7.1.2.1 Nonextended Sense. The format of the sense data is determined by the error class. Error classes 0 through 6 use the nonextended sense data format (Table 7-4). Error class 7 is described in Section 7.1.2.2. .pa Table 7-4 Nonextended Sense Data Format ============================================================================== Bit| 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | Byte | | | | | | | | | ============================================================================== 0 | AdValid| Error Class | Error Code | -----|-----------------------------------------------------------------------| 1 | Vendor Unique |Logical Block Address (MSB) | -----|-----------------------------------------------------------------------| 2 | Logical Block Address | -----|-----------------------------------------------------------------------| 3 | Logical Block Address (LSB) | ============================================================================== The address valid (AdValid) bit indicates that the logical block address field contains valid information related to the error code. The error class specifies a class of errors with error classes 0 through 6 being vendor unique. For these classes, the error code is vendor unique. 7.1.2.2 Extended Sense. Error class 7 specifies extended sense. Error code zero specifies the extended sense data format. Error code FH specifies a vendor unique data format for extended sense. Error codes 1H through EH are reserved. The extended sense data format is shown in Table 7-5. Table 7-5 Extended Sense Data Format ============================================================================== Bit| 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | Byte | | | | | | | | | ============================================================================== 0 | Valid | Error Class (7) | Error Code (0) | -----|-----------------------------------------------------------------------| 1 | Segment Number | -----|-----------------------------------------------------------------------| 2 |Filemark| EOM | ILI |Reserved| Sense Key | -----|-----------------------------------------------------------------------| 3 | Information Byte (MSB) | -----|-----------------------------------------------------------------------| 4 | Information Byte | -----|-----------------------------------------------------------------------| 5 | Information Byte | -----|-----------------------------------------------------------------------| 6 | Information Byte (LSB) | -----|-----------------------------------------------------------------------| 7 | Additional Sense Length (n) | -----|-----------------------------------------------------------------------| 8 _ | Additional Sense Bytes | n+7 | | ============================================================================== The information bytes are not defined if the valid bit is zero. If the valid bit is one, the information bytes contain valid information as follows: (1) The unsigned logical block address associated with the sense key, for direct-access devices (Type 0), write-once read-multiple devices (Type 4), and read-only direct-access devices (Type 5). (2) The difference (residue) of the requested length minus the actual length in either bytes or blocks, as determined by the command, for sequential-access devices (Type 1), printer devices (Type 2), and processor devices (Type 3). (Negative values are indicated by two's complement notation.) (3) The difference (residue) of the requested number of blocks minus the actual number of blocks copied or compared for the current segment descriptor of a COPY, COMPARE, or COPY AND VERIFY command. The segment number contains the number of the current segment descriptor if the extended sense is in response to a COPY, COMPARE, or COPY AND VERIFY command. Up to 256 segments are supported beginning with segment zero. The filemark bit indicates that the current command has read a filemark. This bit is only used for sequential-access devices. The end-of-medium (EOM) bit indicates that an end-of-medium condition (end- of-tape, beginning-of-tape, out-of-paper, etc) exists on a sequential access device or printer device. For sequential-access devices, this bit indicates that the unit is at or past the early-warning end-of-tape if the direction was forward or that the command could not be completed because beginning-of-tape was encountered if the direction was reverse. Direct-access devices shall not use this bit; instead, these devices shall report attempts to access beyond the end-of-medium as ILLEGAL REQUEST sense key (see Table 7-6). The incorrect length indicator (ILI) bit indicates that the requested logical block length did not match the logical block length of the data on the medium. The sense keys are described in Tables 7-6 and 7-7. The additional sense length specifies the number of additional sense bytes to follow. If the allocation length of the command descriptor block is too small to transfer all of the additional sense bytes, the additional sense length is not adjusted to reflect the truncation. The additional sense bytes contain command-specific, peripheral-device- specific data, or both kinds of data that further define the nature of the CHECK CONDITION status. The COPY, COMPARE, COPY AND VERIFY, and SEARCH DATA commands define a standard purpose for some of these bytes. Except as described in these commands, the additional sense bytes are vendor unique. .pa Table 7-6 Sense Key (0H-7H) Descriptions ============================================================================== Sense Key Description --------- ------------------------------------------------------------------- 0H NO SENSE. Indicates that there is no specific sense key information to be reported for the designated logical unit. This would be the case for a successful command or a command that received a CHECK CONDITION status because one of the filemark, EOM, or ILI bits is set to one. 1H RECOVERED ERROR. Indicates that the last command completed successfully with some recovery action performed by the target. Details may be determinable by examining the additional sense bytes and the information bytes. 2H NOT READY. Indicates that the logical unit addressed cannot be accessed. Operator intervention may be required to correct this condition. 3H MEDIUM ERROR. Indicates that the command terminated with a nonrecovered error condition that was probably caused by a flaw in the medium or an error in the recorded data. 4H HARDWARE ERROR. Indicates that the target detected a nonrecoverable hardware failure (for example, controller failure, device failure, parity error, etc) while performing the command or during a self test. 5H ILLEGAL REQUEST. Indicates that there was an illegal parameter in the command descriptor block or in the additional parameters supplied as data for some commands (FORMAT UNIT, SEARCH DATA, etc). If the target detects an invalid parameter in the command descriptor block, then it shall terminate the command without altering the medium. If the target detects an invalid parameter in the additional parameters supplied as data, then the target may have already altered the medium. 6H UNIT ATTENTION. Indicates that the removable medium may have been changed or the target has been reset. See 6.1.3 for more detailed information about the unit attention condition. 7H DATA PROTECT. Indicates that a command that reads or writes the medium was attempted on a block that is protected from this operation. The read or write operation is not performed. ============================================================================== .pa Table 7-7 Sense Key (8H-FH) Descriptions ============================================================================== Sense Key Description --------- ------------------------------------------------------------------- 8H BLANK CHECK. Indicates that a write-once read-multiple device or a sequential-access device encountered a blank block while reading or a write-once read-multiple device encountered a nonblank block while writing. 9H Vendor unique. This sense key is available for reporting vendor unique conditions. AH COPY ABORTED. Indicates a COPY, COMPARE, or COPY AND VERIFY command was aborted due to an error condition on the source device, the destination device, or both. (See 7.1.4.2 for additional information about this sense key.) BH ABORTED COMMAND. Indicates that the target aborted the command. The initiator may be able to recover by trying the command again. CH EQUAL. Indicates a SEARCH DATA command has satisfied an equal comparison. DH VOLUME OVERFLOW. Indicates that a buffered peripheral device has reached the end-of-medium and data remains in the buffer that has not been written to the medium. A RECOVER BUFFERED DATA command(s) may be issued to read the unwritten data from the buffer. EH MISCOMPARE. Indicates that the source data did not match the data read from the medium. FH This sense key is reserved. ============================================================================== .pa 7.1.3 INQUIRY Command Peripheral Device Type: All Operation Code Type: Extended Operation Code: 12H Table 7-8 INQUIRY Command ============================================================================== Bit| 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | Byte | | | | | | | | | ============================================================================== 0 | Operation Code | -----|-----------------------------------------------------------------------| 1 | Logical Unit Number | Reserved | -----|-----------------------------------------------------------------------| 2 | Reserved | -----|-----------------------------------------------------------------------| 3 | Reserved | -----|-----------------------------------------------------------------------| 4 | Allocation Length | -----|-----------------------------------------------------------------------| 5 | Vendor Unique | Reserved | Flag | Link | ============================================================================== The INQUIRY command (Table 7-8) requests that information regarding parameters of the target and its attached peripheral device(s) be sent to the initiator. The allocation length specifies the number of bytes that the initiator has allocated for returned INQUIRY data. An allocation length of zero indicates that no INQUIRY data shall be transferred. This condition shall not be considered as an error. Any other value indicates the maximum number of bytes that shall be transferred. The target shall terminate the DATA IN phase when allocation length bytes have been transferred or when all available INQUIRY data have been transferred to the initiator, whichever is less. The INQUIRY command shall return a CHECK CONDITION status only when the target cannot return the requested INQUIRY data. (Implementors note: It is recommended that the INQUIRY data be returned even though the peripheral device may not be ready for other commands.) If an INQUIRY command is received from an initiator with a pending unit attention condition (before the target reports CHECK CONDITION status), the target shall perform the INQUIRY command and shall not clear the unit attention condition. (See 6.1.3.) The INQUIRY data (Table 7-9) contains a five byte header, followed by the vendor unique parameters, if any. .pa Table 7-9 INQUIRY Data ============================================================================== Bit| 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | Byte | | | | | | | | | ============================================================================== 0 | Peripheral Device Type | -----|-----------------------------------------------------------------------| 1 | RMB | Device-Type Qualifier | -----|-----------------------------------------------------------------------| 2 | ISO Version | ECMA Version | ANSI Version | -----|-----------------------------------------------------------------------| 3 | Reserved | -----|-----------------------------------------------------------------------| 4 | Additional Length (n) | ============================================================================== | Vendor Unique Parameters | ============================================================================== 5 _ | Vendor Unique | n+4 | Parameter Bytes | ============================================================================== The peripheral device type is shown in Table 7-10. Table 7-10 Peripheral Device Type ============================================================================== Code Description ------------------------------------------------------------------------------ 00H Direct-access device (e.g., magnetic disk) 01H Sequential-access device (e.g., magnetic tape) 02H Printer device 03H Processor device 04H Write-once read-multiple device (e.g., some optical disks) 05H Read-only direct-access device (e.g., some optical disks) 06H _ 7EH Reserved 7FH Logical unit not present 80H _ FFH Vendor unique ============================================================================== A removable medium (RMB) bit of zero indicates that the medium is not removable. A RMB bit of one indicates that the medium is removable. The device-type qualifier is a seven bit user specified code. This code may be set with switches or by some other means by the target or peripheral device. SCSI devices that do not support this feature shall return all zero bits. This feature allows each user to assign unique codes to each specific type of peripheral device that is supported on the system being used. These codes may then be used by self-configuring software to determine what specific peripheral device is at each logical unit number. This is especially valuable for systems that support multiple types of removable medium. The usage of nonzero code values in the ISO version and ECMA version fields are defined by the International Standards Organization and the European Computer Manufacturers Association, respectively. A zero code value in these fields shall indicate that the target does not claim compliance to the ISO or ECMA versions of SCSI. Note that it is possible to claim compliance to more than one of these SCSI standards. The ANSI version indicates the implemented version of this standard and is defined as shown in Table 7-11. Table 7-11 ANSI Version ============================================================================== Code Description ------------------------------------------------------------------------------ 0H Version is unspecified. (Use this code if you are implementing to this document - it is not published, yet.) 1H This version. This code shall be used by SCSI devices that claim to comply with this standard (upon ANSI publication) 2H _ 7H Reserved ============================================================================== The additional length shall specify the length in bytes of the vendor unique parameters. If the allocation length of the command descriptor block is too small to transfer all of the vendor unique parameters, the additional length shall not be adjusted to reflect the truncation. 7.1.4 COPY Command Peripheral Device Type: All Operation Code Type: Optional Operation Code: 18H Table 7-12 COPY Command ============================================================================== Bit| 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | Byte | | | | | | | | | ============================================================================== 0 | Operation Code | -----|-----------------------------------------------------------------------| 1 | Logical Unit Number | Reserved | -----|-----------------------------------------------------------------------| 2 | Parameter List Length (MSB) | -----|-----------------------------------------------------------------------| 3 | Parameter List Length | -----|-----------------------------------------------------------------------| 4 | Parameter List Length (LSB) | -----|-----------------------------------------------------------------------| 5 | Vendor Unique | Reserved | Flag | Link | ============================================================================== The COPY command (Table 7-12) provides a means to copy data from one logical unit to another or the same logical unit. The logical units may reside on the same SCSI device or different SCSI devices. Some SCSI devices that implement this command may not support copies to or from another SCSI device or third party copies (both logical units reside on other SCSI devices). The parameter list length specifies the length in bytes of the parameters that shall be sent during the DATA OUT phase of the command. A parameter list length of zero indicates that no data shall be transferred. This condition shall not be considered as an error. The COPY parameter list (Table 7-13) begins with a four-byte header that contains the COPY function code and priority. Following the header is one or more segment descriptors. Table 7-13 COPY Parameter List ============================================================================== Bit| 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | Byte | | | | | | | | | ============================================================================== 0 | COPY Function Code | Priority | -----|-----------------------------------------------------------------------| 1 | Vendor Unique | -----|-----------------------------------------------------------------------| 2 | Reserved | -----|-----------------------------------------------------------------------| 3 | Reserved | ============================================================================== | Segment Descriptor(s) | ============================================================================== 0 _ | Segment Descriptor 0 | xx | (See specific table for length.) | -----|-----------------------------------------------------------------------| | . | | . | | . | -----|-----------------------------------------------------------------------| 0 _ | Segment Descriptor n | xx | (See specific table for length.) | ============================================================================== The COPY function code defines a specific format for the segment descriptors. The COPY function codes are defined in Table 7-14. The priority field of the COPY parameter list establishes the relative priority of this COPY command to other commands being executed by the same target. All other commands are assumed to have a priority of 1. Priority0 is the highest priority with increasing values indicating lower priorities. The segment descriptor formats are determined by the COPY function code. The segment descriptor format used for write-once read-multiple devices and for read-only direct-access devices shall be the same as for direct-access devices. The segment descriptor format used for printer devices and for processor devices shall be the same as for sequential-access devices. Thus a COPY from a write-once read-multiple device to a printer device uses the same segment descriptor format as for a COPY from a direct-access device to a sequential-access device. (See Table 7-14.) The segment descriptor formats are described in Tables 7-15 through 7-17. A maximum of 256 segment descriptors are permitted. The segment descriptors are identified by ascending numbers beginning with zero. Table 7-14 COPY Functions ============================================================================== Peripheral Device Type COPY Segment ---------------------- Function Descriptor Source Destination Code Table Comment ------------------------------------------------------------------------------ 00H 01H 00H Table 7-15 00H 02H 00H Table 7-15 00H 03H 00H Table 7-15 04H 01H 00H Table 7-15 Direct Access 04H 02H 00H Table 7-15 to 04H 03H 00H Table 7-15 Sequential Access 05H 01H 00H Table 7-15 05H 02H 00H Table 7-15 05H 03H 00H Table 7-15 01H 00H 01H Table 7-15 Sequential Access 01H 04H 01H Table 7-15 to 03H 00H 01H Table 7-15 Direct Access 03H 04H 01H Table 7-15 00H 00H 02H Table 7-16 00H 04H 02H Table 7-16 Direct Access 04H 00H 02H Table 7-16 to 04H 04H 02H Table 7-16 Direct Access 05H 00H 02H Table 7-16 05H 04H 02H Table 7-16 01H 01H 03H Table 7-17 01H 02H 03H Table 7-17 Sequential Access 01H 03H 03H Table 7-17 to 03H 01H 03H Table 7-17 Sequential Access 03H 02H 03H Table 7-17 03H 03H 03H Table 7-17 ============================================================================== Peripheral device type: 00H Direct-access device 01H Sequential-access device 02H Printer device 03H Processor device 04H Write-once read-multiple device 05H Read-only direct-access device COPY function code: 00H Direct access to sequential access 01H Sequential access to direct access 02H Direct access to direct access 03H Sequential access to sequential access 04H _ 0FH Reserved 10H _ 1FH Vendor unique .pa 7.1.4.1 Errors Detected by the Managing SCSI Device. Two classes of unusual conditions may occur during execution of a COPY command. The first class consists of those unusual conditions detected by the SCSI device that received the COPY command and is managing the execution of the command. These conditions include parity errors while transferring the COPY command and status byte, invalid parameters in the COPY command, invalid segment descriptors, and inability of the SCSI device controlling the COPY functions to continue operating. In the event of such an unusual condition, the SCSI device managing the COPY shall: (1) Terminate the COPY command with a CHECK CONDITION status. (2) Return the sense data in the extended sense format. The valid bit shall be set to one. The segment number shall contain the number of the segment descriptor being processed at the time the unusual condition is detected. The sense key shall contain the sense key code describing the unusual condition. The information bytes shall contain the difference between the number of blocks field in the segment descriptor being processed at the time of the failure and the number of blocks successfully copied. This number is the residue of unprocessed blocks remaining for the segment descriptor. 7.1.4.2 Errors Detected by a Target. The second class of errors consists of unusual conditions detected by the SCSI device transferring data at the request of the SCSI device managing the transfer. The SCSI device managing the COPY command detects unusual conditions by receiving a CHECK CONDITION status from one of the SCSI devices it is managing. It then shall recover the sense data associated with the unusual condition. The SCSI device managing the COPY command may also be the source or destination SCSI device (or both). It shall distinguish between a failure of the management of the COPY and a failure of the data transfer being requested. It shall then create the appropriate sense data internally. After recovering the sense data associated with the detected error, the SCSI device managing the COPY command shall: (1) Terminate the COPY command with a CHECK CONDITION status. (2) Return the sense data in the extended sense format. The valid bit shall be set to one. The segment number shall contain the number of the segment descriptor being processed at the time the unusual condition is detected. The sense key shall be set to COPY ABORTED. The information bytes shall contain the difference between the number of blocks field in the segment descriptor being processed at the time of the failure and the number of blocks successfully copied. This number is the residue of unprocessed blocks remaining for the segment descriptor. The additional sense length shall specify the number of additional sense bytes. The first additional sense byte shall specify the byte number, relative to the first byte of sense data of the beginning of the source logical unit's status byte and sense data. A zero value indicates that no status byte or sense data is being returned for the source logical unit. The first byte of the area pointed to by the first additional sense byte shall contain the status byte from the source logical unit. The subsequent bytes shall contain, unchanged, the sense data recovered from the source logical unit. The second additional sense byte shall specify the byte number, relative to the first byte of sense data of the beginning of the destination logical unit's status byte and sense data. A zero value indicates that no status byte or sense data is being returned for the destination logical unit. The first byte of the area pointed to by the second additional sense byte shall contain the status byte from the destination logical unit. The subsequent bytes shall contain, unchanged, the sense data recovered from the destination logical unit. 7.1.4.3 COPY Function Code 00H and 01H. The format for the segment descriptors for COPY transfers between direct-access and sequential-access devices is specified in Table 7-15. This format is required for COPY function codes 00H or 01H. The segment descriptor may be repeated up to 256 times within the parameter list length specified in the command descriptor block. Table 7-15 Segment Descriptor for COPY Function Codes 00H and 01H ============================================================================== Bit| 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | Byte | | | | | | | | | ============================================================================== 0 | Source Address | Reserved | Source LUN | -----|-----------------------------------------------------------------------| 1 | Destination Address | Reserved | Destination LUN | -----|-----------------------------------------------------------------------| 2 | Sequential-Access Device Block-Length (MSB) | -----|-----------------------------------------------------------------------| 3 | Sequential-Access Device Block-Length (LSB) | -----|-----------------------------------------------------------------------| 4 | Direct-Access Device Number of Blocks (MSB) | -----|-----------------------------------------------------------------------| 5 | Direct-Access Device Number of Blocks | -----|-----------------------------------------------------------------------| 6 | Direct-Access Device Number of Blocks | -----|-----------------------------------------------------------------------| 7 | Direct-Access Device Number of Blocks (LSB) | -----|-----------------------------------------------------------------------| 8 | Direct-Access Device Logical Block Address (MSB) | -----|-----------------------------------------------------------------------| 9 | Direct-Access Device Logical Block Address | -----|-----------------------------------------------------------------------| 10 | Direct-Access Device Logical Block Address | -----|-----------------------------------------------------------------------| 11 | Direct-Access Device Logical Block Address (LSB) | ============================================================================== Source address and destination address fields specify the SCSI devices and the source LUN and destination LUN fields specify the logical units to use for this segment of the COPY command. Some SCSI devices may not support "third- party" COPY in which the copying SCSI device is not the source or destination device. Some SCSI devices only support COPY within the SCSI device and not to other SCSI devices. If an unsupported COPY operation is requested, the command shall be terminated with a CHECK CONDITION status and the sense key shall be set to ILLEGAL REQUEST. The sequential-access device block-length field specifies the block-length to be used on the sequential-access logical unit during this segment of the COPY command. If this block-length is known by the SCSI device managing the COPY to be not supported, the command shall be terminated with a CHECK CONDITION status and the sense key shall be set to ILLEGAL REQUEST. If the block-length is found to be invalid while executing a read or write operation to the sequential-access device, the command shall be terminated with a CHECK CONDITION status and the sense key shall be set to COPY ABORTED. The direct-access device number of blocks field specifies the number of blocks in the current segment. A value of zero indicates that no blocks shall be transferred in this segment. The direct-access device logical block address specifies the starting logical block address on the logical unit for this segment. 7.1.4.4 COPY Function Code 02H. The format for the segment descriptors for COPY transfers among direct-access devices is specified by Table 7-16. This format is required for COPY function code 02H. The segment descriptor may be repeated up to 256 times within the parameter list length specified in the command descriptor block. .pa Table 7-16 Segment Descriptor for COPY Function Code 02H ============================================================================== Bit| 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | Byte | | | | | | | | | ============================================================================== 0 | Source Address | Reserved | Source LUN | -----|-----------------------------------------------------------------------| 1 | Destination Address | Reserved | Destination LUN | -----|-----------------------------------------------------------------------| 2 | Reserved | -----|-----------------------------------------------------------------------| 3 | Reserved | -----|-----------------------------------------------------------------------| 4 | Source Number of Blocks (MSB) | -----|-----------------------------------------------------------------------| 5 | Source Number of Blocks | -----|-----------------------------------------------------------------------| 6 | Source Number of Blocks | -----|-----------------------------------------------------------------------| 7 | Source Number of Blocks (LSB) | -----|-----------------------------------------------------------------------| 8 | Source Logical Block Address (MSB) | -----|-----------------------------------------------------------------------| 9 | Source Logical Block Address | -----|-----------------------------------------------------------------------| 10 | Source Logical Block Address | -----|-----------------------------------------------------------------------| 11 | Source Logical Block Address (LSB) | -----|-----------------------------------------------------------------------| 12 | Destination Logical Block Address (MSB) | -----|-----------------------------------------------------------------------| 13 | Destination Logical Block Address | -----|-----------------------------------------------------------------------| 14 | Destination Logical Block Address | -----|-----------------------------------------------------------------------| 15 | Destination Logical Block Address (LSB) | ============================================================================== The source address and destination address fields specify the SCSI devices and the source LUN and destination LUN specify the logical units to use for this segment of the COPY command. Some SCSI devices may not support "third- party" COPY in which the copying SCSI device is not the source or destination device. Some SCSI devices only support COPY within the SCSI device and not to other SCSI devices. If an unsupported COPY operation is requested, the command shall be terminated with a CHECK CONDITION status and the sense key shall be set to ILLEGAL REQUEST. The source number of blocks field specifies the number of blocks to be transferred from the source device during command execution. The source logical block address field specifies the starting logical block address on the source device. The destination logical block address field specifies the starting logical block address on the destination device. .pa 7.1.4.5 COPY Function Code 03H. The format for the segment descriptors for COPY transfers among sequential-access devices is specified by Table 7-17. This format is required for COPY function code 03H. The segment descriptor may be repeated up to 256 times within the parameter list length specified in the command descriptor block. Table 7-17 Segment Descriptor for COPY Function Code 03H ============================================================================== Bit| 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | Byte | | | | | | | | | ============================================================================== 0 | Source Address | Reserved | Source LUN | -----|-----------------------------------------------------------------------| 1 | Destination Address | Reserved | Destination LUN | -----|-----------------------------------------------------------------------| 2 | Reserved | -----|-----------------------------------------------------------------------| 3 | Reserved | -----|-----------------------------------------------------------------------| 4 | Source Block Length (MSB) | -----|-----------------------------------------------------------------------| 5 | Source Block Length (LSB) | -----|-----------------------------------------------------------------------| 6 | Destination Block Length (MSB) | -----|-----------------------------------------------------------------------| 7 | Destination Block Length (LSB) | -----|-----------------------------------------------------------------------| 8 | Source Number of Blocks (MSB) | -----|-----------------------------------------------------------------------| 9 | Source Number of Blocks | -----|-----------------------------------------------------------------------| 10 | Source Number of Blocks | -----|-----------------------------------------------------------------------| 11 | Source Number of Blocks (LSB) | ============================================================================== Source address and destination address fields specify the SCSI devices and the source LUN and destination LUN fields specify the logical units to use for this segment of the COPY command. Some SCSI devices may not support "third- party" COPY in which the copying SCSI device is not the source or destination device. Some SCSI devices only support COPY within the SCSI device and not to other SCSI devices. If an unsupported COPY operation is requested, the command shall be terminated with a CHECK CONDITION status and the sense key shall be set to ILLEGAL REQUEST. The source block-length field specifies the block-length of the source device for this segment of the COPY. A zero in this field indicates variable block-length. For nonzero values, this field shall match the logical unit's actual block-length. If block-length mismatches are detected by the SCSI device managing the COPY, the command shall be terminated with a CHECK CONDITION status and the sense key shall be set to ILLEGAL REQUEST. If the mismatches are detected during the read operation by the COPY manager, the command shall be terminated with a CHECK CONDITION status and the sense key shall be set to COPY ABORTED. The destination block-length field specifies the block-length to be used on the destination logical unit during the COPY. Destination block-length mismatches are handled in the same manner as source block-length mismatches. The source number of blocks field specifies the number of blocks to be transferred from the source device during this segment. A value of zero indicates that no blocks shall be transferred. 7.1.5 RECEIVE DIAGNOSTIC RESULTS Command Peripheral Device Type: All Operation Code Type: Optional Operation Code: 1CH Table 7-18 RECEIVE DIAGNOSTIC RESULTS Command ============================================================================== Bit| 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | Byte | | | | | | | | | ============================================================================== 0 | Operation Code | -----|-----------------------------------------------------------------------| 1 | Logical Unit Number | Reserved | -----|-----------------------------------------------------------------------| 2 | Reserved | -----|-----------------------------------------------------------------------| 3 | Allocation Length (MSB) | -----|-----------------------------------------------------------------------| 4 | Allocation Length (LSB) | -----|-----------------------------------------------------------------------| 5 | Vendor Unique | Reserved | Flag | Link | ============================================================================== The RECEIVE DIAGNOSTIC RESULTS command (Table 7-18) requests analysis data be sent to the initiator after completion of a SEND DIAGNOSTIC command (see 7.1.6). The allocation length shall specify the number of bytes that the initiator has allocated for returned diagnostic data. An allocation length of zero indicates that no diagnostic data shall be transferred. Any other value indicates the maximum number of bytes that shall be transferred. The target terminates the DATA IN phase when allocation length bytes have been transferred or when all available diagnostic data have been transferred to the initiator, whichever is less. The diagnostic data returned is vendor unique. NOTE: Although diagnostic software is generally device-specific, this command and the SEND DIAGNOSTIC command provide a means to isolate the operating system software from the device-specific diagnostic software. Hence the operating system can remain device-independent. This also allows diagnostic software to be more easily ported to other operating systems. .pa 7.1.6 SEND DIAGNOSTIC Command Peripheral Device Type: All Operation Code Type: Optional Operation Code: 1DH Table 7-19 SEND DIAGNOSTIC Command ============================================================================== Bit| 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | Byte | | | | | | | | | ============================================================================== 0 | Operation Code | -----|-----------------------------------------------------------------------| 1 | Logical Unit Number | Reserved |SelfTest| DevOfL | UnitOfL| -----|-----------------------------------------------------------------------| 2 | Reserved | -----|-----------------------------------------------------------------------| 3 | Parameter List Length (MSB) | -----|-----------------------------------------------------------------------| 4 | Parameter List Length (LSB) | -----|-----------------------------------------------------------------------| 5 | Vendor Unique | Reserved | Flag | Link | ============================================================================== The SEND DIAGNOSTIC command (Table 7-19) requests the target to perform diagnostic tests on itself, on the attached peripheral devices, or on both. This command is usually followed by a RECEIVE DIAGNOSTIC RESULTS command, except when the self test (SelfTest) bit is one. The parameter list length specifies the length in bytes of the parameter list that shall be transferred during the DATA OUT phase. A parameter list length of zero indicates that no data shall be transferred. This condition shall not be considered as an error. The parameter list is vendor unique. A logical unit off-line (UnitOfL) bit of one enables write operations on user medium or operations that affect user visible medium positioning. An SCSI device off-line (DevOfL) bit of one enables diagnostic operations that may adversely affect operations to other logical units on the same target. The logical unit off-line and SCSI device off-line bits are generally set by operating system software, while the parameter list is prepared by diagnostic application software. Thus, by preventing operations that are not enabled by these bits, the target assists the operating system in protecting its resources. A self test bit of one directs the target to complete its default self test. If the self test is requested, the parameter list length shall be set to zero and no data shall be transferred. If the self test successfully passes, the command shall be terminated with a GOOD status; otherwise, the command shall be terminated with a CHECK CONDITION status and, if extended sense is implemented, the sense key shall be set to HARDWARE ERROR. NOTE: See the note under the RECEIVE DIAGNOSTIC RESULTS command (7.1.5). .pa 7.2 Group 1 Commands for All Device Types. These commands shall be as listed in Table 7-20. Table 7-20 Group 1 Commands for All Device Types ============================================================================== Operation Code Type Command Name Section ------------------------------------------------------------------------------ 20H V 21H V 22H V 23H V 24H V 25H * 26H V 27H V 28H * 29H V 2AH * 2BH * 2CH V 2DH V 2EH * 2FH * 30H * 31H * 32H * 33H * 34H R 35H R 36H R 37H R 38H R 39H O COMPARE 7.2.1 3AH O COPY AND VERIFY 7.2.2 3BH R 3CH R 3DH R 3EH R 3FH R ============================================================================== Key: O = Command implementation is optional. R = Operation code is reserved for future standardization. V = Operation code is available for vendor unique commands. * = These operation codes may have different meanings for specific types of peripheral devices. (See the appropriate section for further information.) .pa 7.2.1 COMPARE Command Peripheral Device Type: All Operation Code Type: Optional Operation Code: 39H Table 7-21 COMPARE Command ============================================================================== Bit| 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | Byte | | | | | | | | | ============================================================================== 0 | Operation Code | -----|-----------------------------------------------------------------------| 1 | Logical Unit Number | Reserved | -----|-----------------------------------------------------------------------| 2 | Reserved | -----|-----------------------------------------------------------------------| 3 | Parameter List Length (MSB) | -----|-----------------------------------------------------------------------| 4 | Parameter List Length | -----|-----------------------------------------------------------------------| 5 | Parameter List Length (LSB) | -----|-----------------------------------------------------------------------| 6 | Reserved | -----|-----------------------------------------------------------------------| 7 | Reserved | -----|-----------------------------------------------------------------------| 8 | Reserved | -----|-----------------------------------------------------------------------| 9 | Vendor Unique | Reserved | Flag | Link | ============================================================================== The COMPARE command (Table 7-21) provides the means to compare data from one logical unit with another or the same logical unit in a manner similar to the COPY command. This command functions in the same manner as the COPY command, except that the data from the source is compared on a byte-by-byte basis with the data >From the destination. The parameter list transferred to the target is the same as for the COPY command. This parameter list contains the information to identify the logical units involved in the comparison and the length of the comparison. (See 7.1.4 for additional information about the COPY command.) If the comparison is unsuccessful, the command shall be terminated with a CHECK CONDITION status and the sense key shall be set to MISCOMPARE. The remaining fields in the extended sense shall be set as documented in the COPY command. .pa 7.2.2 COPY AND VERIFY Command Peripheral Device Type: All Operation Code Type: Optional Operation Code: 3AH Table 7-22 COPY AND VERIFY Command ============================================================================== Bit| 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | Byte | | | | | | | | | ============================================================================== 0 | Operation Code | -----|-----------------------------------------------------------------------| 1 | Logical Unit Number | Reserved | BytChk |Reserved| -----|-----------------------------------------------------------------------| 2 | Reserved | -----|-----------------------------------------------------------------------| 3 | Parameter List Length (MSB) | -----|-----------------------------------------------------------------------| 4 | Parameter List Length | -----|-----------------------------------------------------------------------| 5 | Parameter List Length (LSB) | -----|-----------------------------------------------------------------------| 6 | Reserved | -----|-----------------------------------------------------------------------| 7 | Reserved | -----|-----------------------------------------------------------------------| 8 | Reserved | -----|-----------------------------------------------------------------------| 9 | Vendor Unique | Reserved | Flag | Link | ============================================================================== The COPY AND VERIFY command (Table 7-22) performs the same function as the COPY command, except that a verification of the data written to the destination logical unit is performed after the data is written. The parameter list transferred to the target is the same as for the COPY command. This parameter list contains the information to identify the logical units involved in the copy and the length of the copy. (See 7.1.4 for additional information about the COPY command.) A byte check (BytChk) bit of zero causes the verification to be simply a medium verification (CRC, ECC, etc). A BytChk bit of one causes a byte-by- byte comparison of data written to the destination logical unit and the data read from the source logical unit. If the comparison is unsuccessful, the command shall be terminated with a CHECK CONDITION status and the sense key shall be set to MISCOMPARE. The remaining fields in the extended sense shall be set as documented in the COPY command. .pa 7.3 Group 2 Commands for All Device Types. The Group 2 commands (operation codes 40H through 5FH) are all reserved for future standardization. 7.4 Group 3 Commands for All Device Types. The Group 3 commands (operation codes 60H through 7FH) are all reserved for future standardization. 7.5 Group 4 Commands for All Device Types. The Group 4 commands (operation codes 80H through 9FH) are all reserved for future standardization. 7.6 Group 5 Commands for All Device Types. The Group 5 commands with operation codes A0H through AFH are vendor unique. The Group 5 commands with operation codes B0H through BFH are reserved for future standardization. 7.7 Group 6 Commands for All Device Types. The Group 6 commands (operation codes C0H through DFH) are all vendor unique. 7.8 Group 7 Commands for All Device Types. The Group 7 commands (operation codes E0H through FFH) are all vendor unique. .pa