SYMBOL
GAP
GPL
H/HDS
HLT
HUT
LOCK
MFM
MT
N
NCN
ND
OW
PCN
POLL
PRETRK
R
Table 16 – Description of Command Symbols
NAME
Gap Length
Head Address
Head Load Time
Head Unload
Time
MFM/FM Mode
Selector
Multi-Track
Selector
Sector Size Code
New Cylinder
Number
Non-DMA Mode
Flag
Overwrite
Present Cylinder
Number
Polling Disable
Precompensation
Start Track
Number
Sector Address
DESCRIPTION
Alters Gap 2 length when using Perpendicular Mode.
The Gap 3 size. (Gap 3 is the space between sectors excluding the
VCO synchronization field).
Selected head: 0 or 1 (disk side 0 or 1) as encoded in the sector ID
field.
The time interval that FDC waits after loading the head and before
initializing a read or write operation. Refer to the Specify command
for actual delays.
The time interval from the end of the execution phase (of a read or
write command) until the head is unloaded. Refer to the Specify
command for actual delays.
Lock defines whether EFIFO, FIFOTHR, and PRETRK parameters of
the CONFIGURE COMMAND can be reset to their default values by
a “software Reset”. (A reset caused by writing to the appropriate bits
of either the DSR or DOR)
A one selects the double density (MFM) mode. A zero selects single
density (FM) mode.
When set, this flag selects the multi-track operating mode. In this
mode, the FDC treats a complete cylinder under head 0 and 1 as a
single track. The FDC operates as this expanded track started at the
first sector under head 0 and ended at the last sector under head 1.
With this flag set, a multitrack read or write operation will
automatically continue to the first sector under head 1 when the FDC
finishes operating on the last sector under head 0.
This specifies the number of bytes in a sector. If this parameter is
"00", then the sector size is 128 bytes. The number of bytes
transferred is determined by the DTL parameter. Otherwise the
sector size is (2 raised to the "N'th" power) times 128. All values up
to "07" hex are allowable. "07"h would equal a sector size of 16k. It
is the user's responsibility to not select combinations that are not
possible with the drive.
N
SECTOR SIZE
00
128 Bytes
01
256 Bytes
02
512 Bytes
03
1024 Bytes
…
…
07
16K Bytes
The desired cylinder number.
Write ‘0’. This part does not support non-DMA mode.
The bits D0-D3 of the Perpendicular Mode Command can only be
modified if OW is set to 1. OW id defined in the Lock command.
The current position of the head at the completion of Sense Interrupt
Status command.
When set, the internal polling routine is disabled. When clear, polling
is enabled.
Programmable from track 00 to FFH.
The sector number to be read or written. In multi-sector transfers,
this parameter specifies the sector number of the first sector to be
read or written.
SMSC DS – LPC47M192
Page 46
DATASHEET
Rev. 03/30/05