LPC47M182 SMSC Corporation, LPC47M182 Datasheet - Page 56

• Manufacturer Part Number: LPC47M182
• Description: ADVANCED I/O CONTROLLER WITH MOTHERBOARD GLUE LOGIC
• Manufacturer: SMSC Corporation

6.10
Revision 1.8 SMSC/Non-SMSC Register Sets (02-24-05)
DS0, DS1
SYMBOL
D0, D1
H/HDS
EFIFO
RQM and DIO must both equal “1” before the result bytes may be read. After all the result bytes have
been read, the RQM and DIO bits switch to “1” and “0” respectively, and the CB bit is cleared, indicating
that the FDC is ready to accept the next command.
Command Set/Descriptions
Commands can be written whenever the FDC is in the command phase. Each command has a unique set
of needed parameters and status results. The FDC checks to see that the first byte is a valid command
and, if valid, proceeds with the command. If it is invalid, an interrupt is issued. The user sends a Sense
Interrupt Status command which returns an invalid command error. Refer to Table 6.16 for explanations of
the various symbols used. Table 6.17 lists the required parameters and the results associated with each
command that the FDC is capable of performing.
GAP
EOT
GPL
HUT
DTL
HLT
DIR
EIS
EC
C
D
Cylinder Address
Disk Drive Select
Direction Control
Head Load Time
Drive Select 0-1
Enable Implied
Special Sector
Head Address
Enable Count
Head Unload
Data Pattern
Enable FIFO
End of Track
Gap Length
NAME
Seek
Time
Size
Table 6.16 – Description of Command Symbols
The currently selected address; 0 to 255.
The pattern to be written in each sector data field during formatting.
Designates which drives are perpendicular drives on the
Perpendicular Mode Command. A “1” indicates a perpendicular
drive.
If this bit is 0, then the head will step out from the spindle during a
relative seek. If set to a 1, the head will step in toward the spindle.
By setting N to zero (00), DTL may be used to control the number of
bytes transferred in disk read/write commands. The sector size (N =
0) is set to 128. If the actual sector (on the diskette) is larger than
DTL, the remainder of the actual sector is read but is not passed to
the host during read commands; during write commands, the
remainder of the actual sector is written with all zero bytes. The CRC
check code is calculated with the actual sector. When N is not zero,
DTL has no meaning and should be set to FF HEX.
When this bit is “1” the “DTL” parameter of the Verify command
becomes SC (number of sectors per track).
This active low bit when a 0, enables the FIFO. A “1” disables the
FIFO (default).
When set, a seek operation will be performed before executing any
read or write command that requires the C parameter in the
command phase. A “0” disables the implied seek.
The final sector number of the current track.
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.
DATASHEET
DS1
0
0
56
DS0
0
1
Drive 0
Drive 1
DESCRIPTION
DRIVE
Advanced I/O Controller with Motherboard GLUE Logic
SMSC LPC47M182
Datasheet