SCH3112I-NE SMSC [SMSC Corporation], SCH3112I-NE Datasheet - Page 88

• Manufacturer Part Number: SCH3112I-NE
• Description: LPC IO with 8042 KBC, Reset Generation, HWM and Multiple Serial Ports
• Manufacturer: SMSC [SMSC Corporation]

Rev 0.2 (09-28-04)
SE
0
1
1
0
1
.
E
F
64
4
..
56
60
2M
The Seek, Relative Seek, and Recalibrate commands have no result phase. The Sense Interrupt
Status command must be issued immediately after these commands to terminate them and to provide
verification of the head position (PCN). The H (Head Address) bit in ST0 will always return a “0”. If a
Sense Interrupt Status is not issued, the drive will continue to be BUSY and may affect the operation
of the next command.
SENSE DRIVE STATUS
Sense Drive Status obtains drive status information. It has not execution phase and goes directly to
the result phase from the command phase. Status Register 3 contains the drive status information.
Specify
The Specify command sets the initial values for each of the three internal times. The HUT (Head
Unload Time) defines the time from the end of the execution phase of one of the read/write commands
to the head unload state. The SRT (Step Rate Time) defines the time interval between adjacent step
pulses. Note that the spacing between the first and second step pulses may be shorter than the
remaining step pulses. The HLT (Head Load Time) defines the time between when the Head Load
signal goes high and the read/write operation starts. The values change with the data rate speed
selection and are documented in
DMA operation is selected by the ND bit. When ND is “0”, the DMA mode is selected. This part does
not support non-DMA mode. In DMA mode, data transfers are signaled by the DMA request cycles.
Configure
The Configure command is issued to select the special features of the FDC. A Configure command
need not be issued if the default values of the FDC meet the system requirements.
128
8
..
112
120
IC
11
00
01
1M
256
16
..
224
240
500K
HUT
Table 7.24 Drive Control Delays (ms)
Table 7.23 Interrupt Identification
426
26.7
..
373
400
300K
INTERRUPT DUE TO
Polling
Normal termination of Seek or Recalibrate command
Abnormal termination of Seek or Recalibrate command
Table
DATASHEET
LPC IO with 8042 KBC, Reset Generation, HWM and Multiple Serial Ports
512
32
..
448
480
7.24. The values are the same for MFM and FM.
250K
72
4
3.75
..
0.5
0.25
2M
8
7.5
..
1
0.5
1M
16
15
..
2
1
500K
SRT
26.7
25
..
3.33
1.67
300K
SMSC SCH311X
Datasheet
32
30
..
4
2
250K