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 nPCI_RESET signal. These registers are not affected by soft
resets.
Table 68 - Floppy Disk Controller, Logical Device 0 [Logical Device Number = 0x00]
NAME
REG INDEX
DEFINITION
STATE
FDD Mode Register
0xF0 R/W Bit[0] Floppy Mode
C
= 0
= 1
Normal Floppy Mode (default)
Enhanced Floppy Mode 2 (OS2)
Default = 0x0E
on VCC POR,
VTR POR and
HARD RESET
Bit[1] FDC DMA Mode
= 0
= 1
Burst Mode is enabled
Non-Burst Mode (default)
Bit[3:2] Interface Mode
= 11
= 10
= 01
= 00
AT Mode (default)
(Reserved)
PS/2
Model 30
Bit[4] Reserved
Bit[5] Reserved, set to zero
Bit[6] FDC Output Type Control
= 0
= 1
FDC outputs are OD12 open drain (default)
FDC outputs are O12 push-pull
Bit[7] FDC Output Control
= 0
= 1
FDC outputs active (default)
FDC outputs tri-stated
Note: Bits 6 & 7 do not affect the parallel port FDC
pins.
FDD Option Register
0xF1 R/W Bit[0] Forced Write Protect
C
= 0 Inactive (default)
Default = 0x00
on VCC POR,
VTR POR and
HARD RESET
= 1 FDD nWRTPRT input is forced active when
either of the drives has been selected.
nWRTPRT (to the FDC Core) = WP (FDC SRA
register, bit 1) = (nDS0 AND Forced Write Protect)
OR (nDS1 AND Forced Write Protect) OR nWRTPRT
(from the FDD Interface) OR Floppy Write Protect
Note: The Floppy Write Protect bit is in the Device
Disable register.
Note: Boot floppy is always drive 0.
Note: the Force Write Protect bit also applies to the
Parallel Port FDC.
Bit[1] Reserved
Bits[3:2] Density Select
= 00
= 01
= 10
= 11
Normal (default)
Normal (reserved for users)
1 (forced to logic "1")
0 (forced to logic "0")
Bit[7:4] Reserved.
0xF2 R/W Bits[1:0] Floppy Drive A Type
Bits[3:2] Floppy Drive B Type
FDD Type Register
C
C
Default = 0xFF
on VCC POR,
VTR POR and
HARD RESET
Bits[5:4] Reserved (could be used to store Floppy
Drive C type)
Bits[7:6] Reserved (could be used to store Floppy
Drive D type)
Note: The LPC47M10x supports two floppy drives
0xF3 R
Reserved, Read as 0 (read only)
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