LPC47U332 View Datasheet(PDF) - SMSC -> Microchip
Part Name
Description
MFG CO.
LPC47U332
SMSC -> Microchip
'LPC47U332' PDF : 252 Pages View PDF
The amount of data which can be handled with
a single command to the FDC depends upon
MT (multi-track) and N (number of bytes/sector).
The Multi-Track function (MT) allows the FDC to
read data from both sides of the diskette. For a
particular cylinder, data will be transferred
starting at Sector 1, Side 0 and completing the
last sector of the same track at Side 1.
If the host terminates a read or write operation
in the FDC, the ID information in the result
phase is dependent upon the state of the MT bit
and EOT byte. Refer to
Table 23.
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 24 describes the effect of
the SK bit on the Read Data command
execution and results. Except where noted in
Table 24, the C or R value of the sector address
is automatically incremented (see Table 26).
Table 23 - Effects of MT and N Bits
MAXIMUM TRANSFER FINAL SECTOR READ
MT N
CAPACITY
FROM DISK
0 1 256 x 26 = 6,656
26 at side 0 or 1
1 1 256 x 52 = 13,312
26 at side 1
0 2 512 x 15 = 7,680
15 at side 0 or 1
1 2 512 x 30 = 15,360
15 at side 1
0 3 1024 x 8 = 8,192
8 at side 0 or 1
1 3 1024 x 16 = 16,384
16 at side 1
59
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