Specifications

ATAPI For Streaming Tape QIC-157 Rev B
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6.8.6.12.Log Parameters
This section defines the descriptors and pages for log parameters that may be used with Devices.
The log page codes for Devices are defined in Table 6-21.
Table 6-21 Log Page Codes
Page Code Description Reference
00h Supported Log Pages 6.8.6.29 on page 55
01h Reserved
02h Error Counter Page (Write) Page 6.8.6.38 on page 56
03h Error Counter Page (Read) Page 6.8.6.38 on page 56
04h - 30h Reserved
31h Tape Capacity Page 6.8.6.39 on page 58
32h - 3Eh Vendor Specific
3Fh Reserved
This section describes the log page structure and the log pages that are applicable to all Devices. Each
log page begins with a four-byte page header followed by zero or more variable-length log parameters
defined for that page.
Table 6-22 Log Page Format
Bit
Byte
7 6 5 4 3 2 1 0
0 Reserved Page Code
1 Reserved
2 (MSB) Page Length (n-3)
3 (LSB)
Log Parameter(s)
4 Log Parameter (First)
x+3 (Length x)
n-y Log Parameter (Last)
n (Length y)
The Page Code field identifies which log page is being transferred.
The Page Length field specifies the length in bytes of the following log parameters. If the Host sends
a Page Length that results in the truncation of any parameter, the command shall terminate with
“Check Condition” status. The Sense Key shall be set to ILLEGAL REQUEST with the Additional
Sense Code set to INVALID FIELD IN PARAMETER LIST.
[Editor's Note: Due to hardware restrictions all pages should be padded to a multiple of 4 length.]
Most log pages contain one or more special data structures called log parameters. Log parameters may
be data counters that record a count of a particular event (or events) or log parameters may be list
parameters (strings) which contain a description of a particular event.