FDC37M817-MS Standard Microsystems (SMSC), FDC37M817-MS Datasheet - Page 38

• Manufacturer Part Number: FDC37M817-MS
• Manufacturer: Standard Microsystems (SMSC)

Specifications of FDC37M817-MS

• Pin Count: 100
• Lead Free Status / RoHS Status: Compliant

Commands can be written whenever the FDC is in
the command phase.
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.
C
D
D0, D1
DIR
DS0, DS1
DTL
EC
EFIFO
EIS
EOT
GAP
GPL
H/HDS
SYMBOL
Cylinder
Address
Data Pattern
Drive Select 0-
1
Direction
Control
Disk Drive
Select
Special Sector
Size
Enable Count
Enable FIFO
Enable Implied
Seek
End of Track
Gap Length
Head Address
If
NAME
it
Each command has a
Table 17 - Description of Command Symbols
is
Alters Gap 2 length when using Perpendicular Mode.
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.
DS1
0
0
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.
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.
COMMAND SET/DESCRIPTIONS
invalid,
DS0
0
1
an
Drive 0
Drive 1 (not implemented)
38
interrupt is issued.
Interrupt Status command which returns an invalid
command error.
explanations of the various symbols used. Table
18 lists the required parameters and the results
associated with each command that the FDC is
capable of performing.
DESCRIPTION
Refer to Table 17 for
The user sends a Sense