FDC37C932APM View Datasheet(PDF) - SMSC -> Microchip
Part Name
Description
Manufacturer
FDC37C932APM
SMSC -> Microchip
FDC37C932APM Datasheet PDF : 280 Pages
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At the completion of the Read Data command,
the head is not unloaded until after the Head
Unload Time Interval (specified in the Specify
command) has elapsed. If the host issues
another command before the head unloads,
then the head settling time may be saved
between subsequent reads.
If the FDC detects a pulse on the nINDEX pin
twice without finding the specified sector
(meaning that the diskette's index hole passes
through index detect logic in the drive twice), the
FDC sets the IC code in Status Register 0 to
"01" indicating abnormal termination, sets the
ND bit in Status Register 1 to "1" indicating a
sector not found, and terminates
the Read Data Command.
After reading the ID and Data Fields in each
sector, the FDC checks the CRC bytes. If a
CRC error occurs in the ID or data field, the
FDC sets the IC code in Status Register 0 to
"01" indicating abnormal termination, sets the
DE bit flag in Status Register 1 to "1", sets the
DD bit in Status Register 2 to "1" if CRC is
incorrect in the ID field, and terminates the Read
Data Command. Table 23 describes the effect
of the SK bit on the Read Data command
execution and results. Except where noted in
Table 23, the C or R value of the sector address
is automatically incremented (see Table 25).
Table 22 - Effects of MT and N Bits
MAXIMUM TRANSFER
MT N
CAPACITY
FINAL SECTOR READ
FROM DISK
0 1 256 x 26 = 6,656
1 1 256 x 52 = 13,312
0 2 512 x 15 = 7,680
26 at side 0 or 1
26 at side 1
15 at side 0 or 1
1 2 512 x 30 = 15,360
0 3 1024 x 8 = 8,192
1 3 1024 x 16 = 16,384
15 at side 1
8 at side 0 or 1
16 at side 1
SK BIT
VALUE
0
Table 23 - Skip Bit vs Read Data Command
DATA ADDRESS
MARK TYPE
RESULTS
ENCOUNTERED
SECTOR CM BIT OF
DESCRIPTION OF
READ? ST2 SET?
RESULTS
Normal Data
Yes
No
Normal termination.
0 Deleted Data
Yes
Yes
Address not incremented.
Next sector not searched for.
1 Normal Data
1 Deleted Data
Normal termination.
Yes
No
Normal termination. Sector
No
Yes
not read ("skipped").
57
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