fdc37m707 Standard Microsystems Corp., fdc37m707 Datasheet - Page 36

• Manufacturer Part Number: fdc37m707
• Description: Fdc37m707 Enhanced Super I/o Controller With Wake-up Features
• Manufacturer: Standard Microsystems Corp.

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.
C
D
D0, D1
DIR
DS0, DS1
DTL
EC
EFIFO
EIS
EOT
GAP
GPL
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
NAME
If it is invalid, an
Table 17 - Description of Command Symbols
COMMAND SET/DESCRIPTIONS
The currently selected address; 0 to 255.
The pattern to be written in each sector data field during formatting.
Designates
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.
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.
Alters Gap 2 length when using Perpendicular Mode.
The Gap 3 size. (Gap 3 is the space between sectors excluding the
VCO synchronization field).
DS0
0
1
which
Drive 0
Drive 1 (not implemented)
36
drives
interrupt is issued.
Interrupt Status command which returns an
invalid command error. Refer to Table 17 for
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
are
A "1" indicates a perpendicular
perpendicular
The user sends a Sense
drives
on
the