FDC37M81 SMSC [SMSC Corporation], FDC37M81 Datasheet - Page 150

• Manufacturer Part Number: FDC37M81
• Description: PC98/99 Compliant Enhanced Super I/O Controller with Keyboard/Mouse Wake-Up
• Manufacturer: SMSC [SMSC Corporation]

SMSC Defined Logical Device Configuration Registers
The SMSC Specific Logical Device Configuration Registers reset to their default values only on hard
resets generated by Vcc or VTR POR (as shown) or the RESET_DRV signal. These registers are not
affected by soft resets.
FDD Mode Register
Default = 0x0E
on VCC POR, VTR
POR and HARD
RESET
FDD Option
Register
Default = 0x00
on VCC POR, VTR
POR and HARD
RESET
Table 58 - Floppy Disk Controller, Logical Device 0 [Logical Device Number = 0x00]
NAME
REG INDEX
0xF0 R/W
0xF1 R/W
Bit[0] Floppy Mode
Bit[1] FDC DMA Mode
= 0
= 1
Bit[3:2] Interface Mode
= 11
= 10
= 01
= 00
Bit[4] Reserved
Bit[5] Reserved, set to zero
Bit[6] FDC Output Type Control
= 0
= 1
Bit[7] FDC Output Control
= 0
= 1
Note: Bits 6 & 7 do not affect the parallel port FDC
pins.
Bit[0] Forced Write Protect 0
= 0
= 1
Bit[1] Reserved
Bits[3:2] Density Select
= 00
= 01
= 10
= 11
Bit[7:4] Reserved.
nWRTPRT (to the FDC Core) = (nDS0 AND FORCE
WRTPRT) OR nWRTPRT (from the FDD Interface)
Note: Boot floppy is always drive 0.
Note: the Force Write Protect 0 bit also applies to the
Parallel Port FDC.
= 0
= 1
the drive has been selected.
Inactive (default)
FDD nWRTPRT input is forced active when
Normal Floppy Mode (default)
Enhanced Floppy Mode 2 (OS2)
Burst Mode is enabled
Non-Burst Mode (default)
AT Mode (default)
(Reserved)
PS/2
Model 30
FDC outputs are OD24 open drain (default)
FDC outputs are O24 push-pull
FDC outputs active (default)
FDC outputs tri-stated
Normal (default)
Normal (reserved for users)
1 (forced to logic "1")
0 (forced to logic "0")
150
DEFINITION
STATE
C
C