User Guide

Ampex 1308911-02 D-13
MSR Diagnostic Status Information Physical Block Related Status Field
D.4 Physical Block Related Status Field
Table D-3 describes the arrangement and content of the Physical Block Related Status Field
data structure.
An Ampex SCSI tape drive gathers Physical Block Related Status during each Physical Block
operation and relates to data path status collected throughout the entire 16 scans (5 ms
intervals). There are two ECC decoder paths for which status is collected in each scan. For C1
and C2, these correspond to Channel 1 and Channel 2 tracks on tape. For C3, they correspond
to low and high byte sections of data, shuffled with respect to tape tracks.
Table D-3. Physical Block Related Status Parameters
Byte Bit Description
0 7-0 C1 EDAC P-Bus Setting - internal status for factory use only.
1 7-0 C2 EDAC P-Bus Setting - internal status for factory use only.
2 7-0 C3 EDAC P-Bus Setting - internal status for factory use only.
3 7-0 Event Placement Index of PB - Contains highest scan number
(0-15) for which information was collected. Normally set to 15
because status is collected for 16 scans before Physical Block
related status is updated.
4 7-0 Physical Block Type - Specifies type of PBDF event being
reported in Physical Block Related Status: Successful Read (0),
Successful Write (1), Loop (2), Early Rewrite (3), Late Rewrite
(4), or Unsuccessful Read (5).
5-35 Reserved
36-37 15-0 C1 Generated Erasures, Head P1
38-39 15-0 C1 Generated Erasures, Head P2
40-41 15-0 C1 Generated Erasures, Head P3
42-43 15-0 C1 Generated Erasures, Head P4
44-45 15-0 C1 Generated Erasures, Worst P1 Track
46-47 15-0 C1 Generated Erasures, Worst P2 Track
48-49 15-0 C1 Generated Erasures, Worst P3 Track
50-51 15-0 C1 Generated Erasures, Worst P4 Track
52 7-4 Scan Number with Worst C1 Erasure Count, Head P4
52 3-0 Scan Number with Worst C1 Erasure Count, Head P3
53 7-4 Scan Number with Worst C1 Erasure Count, Head P2
53 3-0 Scan Number with Worst C1 Erasure Count, Head P1