LPC47M112_07 SMSC [SMSC Corporation], LPC47M112_07 Datasheet - Page 30

• Manufacturer Part Number: LPC47M112_07
• Description: Enhanced Super I/O Controller with LPC Interface
• Manufacturer: SMSC [SMSC Corporation]

Enhanced Super I/O Controller with LPC Interface
Datasheet
Normal Floppy Mode
Normal mode. Register 3F3 contains only bits 0 and 1. When this register is read, bits 2 - 7 are ‘0’
Enhanced Floppy Mode 2 (OS2)
Register 3F3 for Enhanced Floppy Mode 2 operation.
DATA RATE SELECT REGISTER (DSR)
Address 3F4 WRITE ONLY
This register is write only. It is used to program the data rate, amount of write precompensation, power down status, and
software reset. The data rate is programmed using the Configuration Control Register (CCR) not the DSR, for PC/AT
and PS/2 Model 30.
Other applications can set the data rate in the DSR. The data rate of the floppy controller is the most recent write of
either the DSR or CCR. The DSR is unaffected by a software reset. A hardware reset will set the DSR to 02H, which
corresponds to the default precompensation setting and 250 Kbps.
SMSC DS – LPC47M112
Bit 7
REG 3F3
REG 3F3 Reserved Reserved
Note:
X
X
X
1
0
DIGITAL OUTPUT REGISTER
RESET
COND.
Bit 6
X
X
X
1
0
L0-CRF2-Bx = Logical Device 0, Configuration Register F2, Bit x.
DIGITAL OUTPUT REGISTER
DB7
DB7
Bit 5
0
RESET
X
X
X
1
0
Bit 1
S/W
0
0
1
1
7
0
Table 5 - Internal 2 Drive Decode - Drives 0 and 1 Swapped
Bit 4
X
X
X
1
0
DB6
DB6
POWER
DOWN
0
6
0
Bit1
X
0
0
1
1
Bit 0
0
1
0
1
DATASHEET
DB5
DB5
Bit 0
Drive Type ID
0
X
Table 6 - Drive Type ID
0
1
0
1
5
0
0
DRIVE SELECT OUTPUTS
COMP2
nDS1
PRE-
Page 30
DB4
DB4
4
0
0
1
1
1
1
0
(ACTIVE LOW)
L0-CRF2 - B1
L0-CRF2 - B3
L0-CRF2 - B5
L0-CRF2 - B7
REGISTER 3F3 - DRIVE TYPE ID
Bit 5
COMP1
PRE-
Floppy Boot Drive
3
0
DB3
DB3
0
nDS0
1
0
1
1
1
COMP0
PRE-
2
0
DB2
DB2
0
L0-CRF2 - B0
L0-CRF2 - B2
L0-CRF2 - B4
L0-CRF2 - B6
MOTOR ON OUTPUTS
nMTR1
nBIT 4
nBIT 4
nBIT 4
nBIT 4
nBIT 4
DRATE
Bit 4
SEL1
(ACTIVE LOW)
tape sel1
tape sel1
1
1
DB1
DB1
DRATE
SEL0
0
0
nMTR0
nBIT 5
nBIT 5
nBIT 5
nBIT 5
nBIT 5
tape sel0
tape sel0
DB0
DB0
Rev. 02-16-07