FDC37C78-HT Standard Microsystems (SMSC), FDC37C78-HT Datasheet - Page 46

• Manufacturer Part Number: FDC37C78-HT
• Manufacturer: Standard Microsystems (SMSC)

Specifications of FDC37C78-HT

• Package Type: TQFP
• Lead Free Status / RoHS Status: Compliant

Read Deleted Data
This command is the same as the Read Data
command, only it operates on sectors that contain
a Deleted Data Address Mark at the beginning of a
Data Field.
Read A Track
This command is similar to the Read Data
command except that the entire data field is read
continuously from each of the sectors of a track.
Immediately after encountering a pulse on the
nINDEX pin, the FDC starts to read all data
fields on the track as continuous blocks of data
without regard to logical sector numbers. If the
FDC finds an error in the ID or DATA CRC check
bytes, it continues to read data from the track and
sets the appropriate error bits at the end of the
command. The FDC compares the ID information
read from each sector with the specified value in
the command and sets the ND flag of Status
VALUE
SK BIT
0
0
1
1
Normal Data
Deleted Data
Normal Data
Deleted Data
DATA ADDRESS
ENCOUNTERED
Table 23 - Skip Bit vs. Read Deleted Data Command
MARK TYPE
SECTOR
READ?
Yes
Yes
Yes
No
46
Table 23 describes the effect of the SK bit on the
Read Deleted Data command execution and
results.
Except where noted in Table 25, the C or R value
of the sector address is automatically incremented
(see Table 26).
Register 1 to a "1" if there is no comparison. Multi-
track or skip operations are not allowed with this
command. The MT and SK bits (bits D7 and D5 of
the first command byte respectively) should always
be set to "0".
This command terminates when the EOT specified
number of sectors has not been read. If the FDC
does not find an ID Address Mark on the diskette
after the second occurrence of a pulse on the IDX
pin, then it sets the IC code in Status Register 0 to
"01" (abnormal termination), sets the MA bit in
Status Register 1 to "1", and terminates the
command.
CM BIT OF
ST2 SET?
Yes
Yes
No
No
RESULTS
Address not
incremented. Next
sector not
searched for.
Normal
termination.
Normal
termination. Sector
not read
("skipped").
Normal
termination.
DESCRIPTION OF
RESULTS