FDC37C78-HT Standard Microsystems (SMSC), FDC37C78-HT Datasheet - Page 29

• Manufacturer Part Number: FDC37C78-HT
• Manufacturer: Standard Microsystems (SMSC)

Specifications of FDC37C78-HT

• Package Type: TQFP
• Lead Free Status / RoHS Status: Compliant

COMMAND SET/DESCRIPTIONS
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. If it is invalid, an interrupt
C
D
D0, D1, D2,
D3
DIR
DS0, DS1
DTL
EC
EFIFO
EIS
EOT
GAP
GPL
H/HDS
SYMBOL
Cylinder Address
Data Pattern
Drive Select 0-3
Direction Control
Disk Drive Select
Special Sector
Size
Enable Count
Enable FIFO
Enable Implied
Seek
End of Track
Gap Length
Head Address
NAME
Each command has a
Table 18 - Description of Command Symbols
The pattern to be written in each sector data field during formatting.
Designates
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
Selected head: 0 or 1 (disk side 0 or 1) as encoded in the sector ID
The currently selected address; 0 to 255.
Perpendicular Mode Command.
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.
VCO synchronization field).
DS1
0
0
1
1
DS0
0
1
0
1
which
29
drive 0
drive 1
drive 2
drive 3
DRIVE
is issued.
Status
command error. Refer to Table 18 or explanations
of the various symbols used. Table 19 lists the
required parameters and the results associated
with each command that the FDC is capable of
performing.
drives
DESCRIPTION
command
are
The user sends a Sense Interrupt
A "1" indicates a perpendicular
perpendicular
which
returns
drives
an
on
invalid
the