FDC37C669_07 SMSC [SMSC Corporation], FDC37C669_07 Datasheet - Page 59

• Manufacturer Part Number: FDC37C669_07
• Description: PC 98/99 Compliant Super I/O Floppy Disk Controller with Infrared Support
• Manufacturer: SMSC [SMSC Corporation]

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
SK BIT
value
0
0
1
1
Normal Data
Deleted Data
Normal Data
Deleted Data
Table 23 - Skip Bit vs. Read Deleted Data Command
DATA ADDRESS
in
ENCOUNTERED
MARK TYPE
the
command
SECTOR
READ?
Yes
Yes
Yes
No
59
Table 25 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).
and
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
termination), sets the MA bit in Status Register
1 to "1", and terminates the command.
CM BIT OF
ST2 SET?
sets the
Yes
Yes
No
No
RESULTS
Register
ND flag of Status Register 1
Address not
incremented.
Next sector not
searched for.
Normal
termination.
Normal
termination.
Sector not read
("skipped").
Normal
termination.
DESCRIPTION
OF RESULTS
0
to
"01"
(abnormal