FDC37C672QFP SMSC Corporation, FDC37C672QFP Datasheet - Page 19

• 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
6.1.1
SMSC FDC37C672
Status Register A (SRA)
Address 3F0 READ ONLY
This register is read-only and monitors the state of the FINTR pin and several disk interface pins in PS/2
and Model 30 modes. The SRA can be accessed at any time when in PS/2 mode. In the PC/AT mode the
data bus pins D0 - D7 are held in a high impedance state for a read of address 3F0.
PS/2 Mode
BIT 0 DIRECTION
Active high status indicating the direction of head movement. A logic "1" indicates inward direction; a logic
"0" indicates outward direction.
BIT 1 nWRITE PROTECT
Active low status of the WRITE PROTECT disk interface input. A logic "0" indicates that the disk is write
protected.
BIT 2 nINDEX
Active low status of the INDEX disk interface input.
BIT 3 HEAD SELECT
Active high status of the HDSEL disk interface input. A logic "1" selects side 1 and a logic "0" selects side
0.
BIT 4 nTRACK 0
Active low status of the TRK0 disk interface input.
BIT 5 STEP
Active high status of the STEP output disk interface output pin.
BIT 6 nDRV2
Active low status of the DRV2 disk interface input pin, indicating that a second drive has been installed.
BIT 7 INTERRUPT PENDING
Active high bit indicating the state of the Floppy Disk Interrupt output.
RESET
COND.
PENDING
PRELIMINARY DATASHEET
INT
7
0
nDRV2
N/A
6
STEP
5
0
Page 19
nTRK0 HDSEL nINDX
N/A
4
3
0
N/A
2
nWP
N/A
1
DIR
0
0
Rev. 10-29-03