82077AA Datasheet, PDF (27/62 Pages) Intel Corporation – CHMOS SINGLE-CHIP FLOPPY DISK CONTROLLER

82077AA
computed and checked against the previously
stored value
Because no data is transferred to the host TC (pin
25) cannot be used to terminate this command By
setting the EC bit to ‘‘1’’ an implicit TC will be issued
to the 82077AA This implicit TC will occur when the
SC value has decrement to 0 (an SC value of 0 will
verify 256 sectors) This command can also be ter-
minated by setting the EC bit to ‘‘0’’ and the EOT
value equal to the final sector to be checked If EC is
set to ‘‘0’’ DTL SC should be programmed to 0FFH
Refer to Table 5-6 and Table 5-7 for information
concerning the values of MT and EC versus SC and
EOT value
Definitions
Sectors Per Side ^e Number of formatted sectors
per each side of the disk
Sectors Remaining ^e Number of formatted sec-
tors left which can be read including side 1 of the
disk if MT is set to ‘‘1’’
Gaps Address Marks ID Fields and Data Fields per
the IBM System 34 (MFM) The particular values
that will be written to the gap and data field are con-
trolled by the values programmed into N SC GPL
and D which are specified by the host during the
command phase The data field of the sector is filled
with the data byte specified by D The ID Field for
each sector is supplied by the host that is four data
bytes per sector are needed by the 82077AA for C
H R and N (cylinder head sector number and sec-
tor size respectively)
After formatting each sector the host must send
new values for C H R and N to the 82077AA for the
next sector on the track The R value (sector num-
ber) is the only value that must be changed by the
host after each sector is formatted This allows the
disk to be formatted with nonsequential sector ad-
dresses (interleaving) This incrementing and for-
matting continues for the whole track until the
82077AA encounters a pulse on the IDX pin again
and it terminates the command
5 1 7 FORMAT TRACK
The FORMAT command allows an entire track to be
formatted After a pulse from the IDX pin is detected
the 82077AA starts writing data on the disk including
Table 5-8 contains typical values for gap fields which
are dependent upon the size of the sector and the
number of sectors on each track Actual values can
vary due to drive electronics
Table 5-7 Verify Command Result Phase Table
MT
EC
SC EOT Value
Termination Result
0
0
SC ^e DTL
Successful Termination
EOT ^s Sectors Per Side
Result Phase Valid
0
0
SC ^e DTL
Unsuccessful Termination
EOT ^l Sectors Per Side
Result Phase Invalid
0
1
SC ^s Sectors Remaining
Successful Termination
AND
Result Phase Valid
EOT ^s Sectors Per Side
0
1
SC ^l Sectors Remaining
Unsuccessful Termination
OR
Result Phase Invalid
EOT ^l Sectors Per Side
1
0
SC ^e DTL
Successful Termination
EOT ^s Sectors Per Side
Result Phase Valid
1
0
SC ^e DTL
Unsuccessful Termination
EOT ^l Sectors Per Side
Result Phase Invalid
1
1
SC ^s Sectors Remaining
Successful Termination
AND
Result Phase Valid
EOT ^s Sectors Per Side
1
1
SC ^l Sectors Remaining
Unsuccessful Termination
OR
Result Phase Invalid
EOT ^l Sectors Per Side
NOTE
If MT is set to ‘‘1’’ and the SC value is greater than the number of remaining formatted sectors on Side 0 verifying will
continue on Side 1 of the disk
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