FDC37C672QFP SMSC Corporation, FDC37C672QFP Datasheet - Page 25

• Manufacturer Part Number: FDC37C672QFP
• Description: ENHANCED SUPER I/O CONTROLLER WITH FAST IR
• Manufacturer: SMSC Corporation

Enhanced Super I/O Controller with Fast IR
Datasheet
Note:
SMSC FDC37C672
Bit 7
X
X
X
1
0
REG 3F3
REG 3F3
DIGITAL OUTPUT REGISTER
Bit 6
Normal Floppy Mode
Normal mode. Register 3F3 contains only bits 0 and 1. When this register is read, bits 2 - 7 are a high
impedance.
Enhanced Floppy Mode 2 (OS2)
Register 3F3 for Enhanced Floppy Mode 2 operation.
For this mode, MEDIA_ID[1:0] pins are gated into bits 6 and 7 of the 3F3 register. These two bits are not
affected by a hard or soft reset.
BIT 7 MEDIA ID 1 READ ONLY (Pin 19) (See Table 6.6)
BIT 6 MEDIA ID 0 READ ONLY (Pin 20) (See Table 6.7)
BITS 5 and 4 Drive Type ID - These bits reflect two of the bits of L0-CRF1. Which two bits these are
depends on the last drive selected in the Digital Output Register (3F2). (See Table 6.8)
BITS 3 and 2 Floppy Boot Drive - These bits reflect the value of L0-CRF1. Bit 3 = L0-CRF1-B7. Bit 2 =
L0-CRF1-B6.
Bits 1 and 0 - Tape Drive Select (READ/WRITE). Same as in Normal and Enhanced Floppy Mode 1.
L0-CRF1-B5 = Logical Device 0, Configuration Register F1, Bit 5
X
X
X
1
0
Bit 5
Tri-state
X
X
X
1
0
Media
DB7
DB7
ID1
Table 6.5 - Internal 2 Drive Decode - Drives 0 and 1 Swapped
Bit 4
PRELIMINARY DATASHEET
X
X
X
1
0
Tri-state
Media
DB6
DB6
ID0
Bit1
X
0
0
1
1
Tri-state
Bit 0
DB5
DB5
X
Drive Type ID
0
1
0
1
DRIVE SELECT OUTPUTS
Tri-state
Page 25
nDS1
DB4
DB4
0
1
1
1
1
(ACTIVE LOW)
Tri-state
Floppy Boot Drive
DB3
DB3
nDS0
1
0
1
1
1
Tri-state
DB2
DB2
tape sel1
nMTR1
tape sel1
MOTOR ON OUTPUTS
nBIT 4
nBIT 4
nBIT 4
nBIT 4
nBIT 4
DB1
DB1
(ACTIVE LOW)
tape sel0
tape sel0
DB0
DB0
nMTR0
nBIT 5
nBIT 5
nBIT 5
nBIT 5
nBIT 5
Rev. 10-29-03