LPC47M192-NW Standard Microsystems (SMSC), LPC47M192-NW Datasheet - Page 57

• Manufacturer Part Number: LPC47M192-NW
• Manufacturer: Standard Microsystems (SMSC)

Specifications of LPC47M192-NW

• Lead Free Status / RoHS Status: Compliant

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 22 and Table 23 for information concerning the values of MT and EC versus
SC and EOT value.
Note:
Format A Track
The Format command allows an entire track to be formatted. After a pulse from the nINDEX pin is detected, the FDC
starts writing data on the disk including gaps, address marks, ID fields, and data fields per the IBM System 34 or
3740 format (MFM or FM respectively). The particular values that will be written to the gap and data field are
controlled by the values programmed into N, SC, GPL, and D which are specified by the host during the command
phase. The data field of the sector is filled with the data byte specified by D. The ID field for each sector is supplied
by the host; that is, four data bytes per sector are needed by the FDC for C, H, R, and N (cylinder, head, sector
number and sector size respectively).
After formatting each sector, the host must send new values for C, H, R and N to the FDC for the next sector on the
track. The R value (sector number) is the only value that must be changed by the host after each sector is formatted.
This allows the disk to be formatted with nonsequential sector addresses (interleaving). This incrementing and
formatting continues for the whole track until the FDC encounters a pulse on the nINDEX pin again and it terminates
the command.
SMSC DS – LPC47M192
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.
MT
0
0
0
0
1
1
1
1
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”.
EC
0
0
1
1
0
0
1
1
SC = DTL
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
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
Table 23 – Verify Command Result Phase Table
SC/EOT VALUE
DATASHEET
Page 57
Success 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
Successful Termination
Result Phase Valid
Unsuccessful Termination
Result Phase Invalid
TERMINATION RESULT
Rev. 03/30/05