IT8702F Datasheet, PDF (116/173 Pages) List of Unclassifed Manufacturers – Super-Low Pin Count Input/Output (LPC I/O)

IT8702F
9.6.12.1 READ ID
The READ ID command is used to find the actual recording head position. It stores the first readable ID field
value into the FDC registers. If the FDC cannot find an ID Address Mark by the time a second INDEX pulse is
received, an abnormal termination will be generated by setting the IC code in the ST0 to 01.
9.6.12.2 Configure
The CONFIGURE command determines some special operation modes of the controller. It needs not to be
issued if the default values of the controller meet the system requirements.
EIS: Enable Implied Seeks. A SEEK operation is performed before a READ, WRITE, SCAN, or VERIFY
command.
0 = Disabled (default).
1 = Enabled.
DFIFO: Disable FIFO.
0 = Enabled.
1 = Disabled (default).
POLLD: Disable polling of the drives.
0 = Enabled (default). When enabled, a single interrupt is generated after a reset.
1 = Disabled.
FIFOTHR: The FIFO threshold in the execution phase of data transfer commands. They are programmable
from 00 to 0F hex (1 byte to 16 bytes). Defaults to 1 byte.
PRETRK: The Precompensation Start Track Number. They are programmable from track 0 to FF hex (track 0
to track 255). Defaults to track 0.
9.6.12.3 RE-CALIBRATE
The RE-CALIBRATE command retracts the FDC read/write head to the track 0 position, resetting the value of
the PCN counter and checking the TRK0# status. If TRK0# is low, the DIR# pin remains low and step pulses
are issued. If TRK0# is high, SE [and EC bits] of the ST0 are set high, and the command is terminated. When
TRK0# remains low for 79 step pulses, the RE-CALIBRATE command is terminated by setting SE and EC
bits of ST0 to high. Consequently, for disks that can accommodate more than 80 tracks, more than one RE-
CALIBRATE command is required to retract the head to the physical track 0.
The FDC is in a non-busy state during the Execution phase of this command, making it possible to issue
another RE-CALIBRATE command in parallel with the current command.
On power-up, software must issue a RE-CALIBRATE command to properly initialize the FDC and the drives
attached.
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IT8702F V0.5