FDC37M817-MS Standard Microsystems (SMSC), FDC37M817-MS Datasheet - Page 67

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

Specifications of FDC37M817-MS

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

LOCK
In order to protect systems with long DMA
latencies against older application software that
can disable the FIFO the LOCK Command has
been added. This command should only be used
by the FDC routines, and application software
should refrain from using it. If an application calls
for the FIFO to be disabled then the CONFIGURE
command should be used.
The LOCK command defines whether the EFIFO,
FIFOTHR, and PRETRK parameters of the
CONFIGURE command can be RESET by the
DOR and DSR registers. When the LOCK bit is
set to logic "1" all subsequent "software RESETS
by the DOR and DSR registers will not change the
previously set parameters to their default values.
All "hardware" RESET from the RESET_DRV pin
will set the LOCK bit to logic "0" and return the
EFIFO, FIFOTHR, and PRETRK to their default
values. A status byte is returned immediately after
issuing a LOCK command. This byte reflects the
value of the LOCK bit set by the command byte.
WGATE
0
0
1
1
GAP
0
1
0
1
Table 28 - Effects of WGATE and GAP Bits
Conventional
Perpendicular
(500 Kbps)
Reserved
(Conventional)
Perpendicular
(1 Mbps)
MODE
67
GAP2 FORMAT
LENGTH OF
ENHANCED DUMPREG
The DUMPREG command is designed to support
system run-time diagnostics and application
software
accommodate the LOCK command and the
enhanced PERPENDICULAR MODE command
the eighth byte of the DUMPREG command has
been modified to contain the additional data from
these two commands.
COMPATIBILITY
The FDC37M81x was designed with software
compatibility in mind.
compatible solution with the older generation
765A/B disk controllers. The FDC also implements
on-board registers for compatibility with the PS/2,
as well as PC/AT and PC/XT, floppy disk controller
subsystems. After a hardware reset of the FDC, all
registers, functions and enhancements default to a
PC/AT, PS/2 or PS/2 Model 30 compatible
operating mode, depending on how the IDENT
and MFM bits are configured by the system BIOS.
22 Bytes
22 Bytes
22 Bytes
41 Bytes
FIELD
development
PORTION OF
WRITTEN BY
WRITE DATA
OPERATION
19 Bytes
38 Bytes
0 Bytes
0 Bytes
GAP 2
It is a fully backwards-
and
debug.
To