Verify
The Verify command is used to verify the data stored on a disk. This command acts exactly like a Read Data command
except that no data is transferred to the host. Data is read from the disk and CRC is computed and checked against the
previously-stored value.
Because data is not transferred to the host, the TC cycle cannot be used to terminate this command. By setting the EC
bit to "1", an implicit TC will be issued to the FDC. This implicit TC will occur when the SC value has decremented
to 0 (an SC value of 0 will verify 256 sectors). This command can also be terminated by setting the EC bit to "0" and the
EOT value equal to the final sector to be checked. If EC is set to "0", DTL/SC should be programmed to 0FFH. Refer to
Table 23 and Table 24 for information concerning the values of MT and EC versus SC and EOT value.
Definitions:
# Sectors Per Side = Number of formatted sectors per each side of the disk.
# Sectors Remaining = Number of formatted sectors left which can be read, including side 1 of the disk if MT is set to
"1".
Table 24 – Verify Command Result Phase Table
MT
EC
SC/EOT VALUE
TERMINATION RESULT
Success Termination
Result Phase Valid
SC = DTL
0
0
EOT ≤ # Sectors Per Side
SC = DTL
EOT > # Sectors Per Side
SC ≤ # Sectors Remaining AND
EOT ≤ # Sectors Per Side
SC > # Sectors Remaining OR
EOT > # Sectors Per Side
SC = DTL
Unsuccessful Termination
Result Phase Invalid
Successful Termination
Result Phase Valid
Unsuccessful Termination
Result Phase Invalid
Successful Termination
Result Phase Valid
Unsuccessful Termination
Result Phase Invalid
Successful Termination
Result Phase Valid
Unsuccessful Termination
Result Phase Invalid
0
0
0
1
1
1
1
0
1
1
0
0
1
1
EOT ≤ # Sectors Per Side
SC = DTL
EOT > # Sectors Per Side
SC ≤ # Sectors Remaining AND
EOT ≤ # Sectors Per Side
SC > # Sectors Remaining OR
EOT > # Sectors Per Side
Note: If MT is set to "1" and the SC value is greater than the number of remaining formatted sectors
on Side 0, verifying will continue on Side 1 of the disk.
SMSC DS – LPC47M14X
Page 53
Rev. 05/02/2000
SMSC [ SMSC CORPORATION ]
