FDC37B727-NS Standard Microsystems (SMSC), FDC37B727-NS Datasheet - Page 38

• Manufacturer Part Number: FDC37B727-NS
• Manufacturer: Standard Microsystems (SMSC)

Specifications of FDC37B727-NS

• Pin Count: 128
• 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. If it is invalid, an interrupt is issued.
C
D
D0, D1
DIR
DS0, DS1
DTL
EC
EFIFO
EIS
EOT
GAP
GPL
H/HDS
HLT
HUT
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
Head Load Time
Head Unload Time The time interval from the end of the execution phase (of a read or
NAME
TABLE 20 - DESCRIPTION OF COMMAND SYMBOLS
Each command has a
COMMAND SET/DESCRIPTIONS
The pattern to be written in each sector data field during formatting.
Designates
Perpendicular Mode Command.
drive.
relative seek. If set to a 1, the head will step in toward the spindle.
DS1 DS0 Drive Selected
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.
initializing a read or write operation. Refer to the Specify command
for actual delays.
write command) until the head is unloaded. Refer to the Specify
command for actual delays.
The currently selected address; 0 to 255.
If this bit is 0, then the head will step out from the spindle during a
The time interval that FDC waits after loading the head and before
0
0
0
1
Drive 0
Drive 1
which
38
The user sends a Sense Interrupt Status
command which returns an invalid command error.
Refer to TABLE 20 for explanations of the various
symbols used. TABLE 21 lists the required
parameters and the results associated with each
command that the FDC is capable of performing.
drives
DESCRIPTION
are
A "1" indicates a perpendicular
perpendicular
drives
on
the