SCH3112I-NE SMSC [SMSC Corporation], SCH3112I-NE Datasheet - Page 85

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

LPC IO with 8042 KBC, Reset Generation, HWM and Multiple Serial Ports
Datasheet
SMSC SCH311X
FORMAT FIELDS
SYSTEM 34 (DOUBLE DENSITY) FORMAT
GAP
4a
80x
4E
SYSTEM 3740 (SINGLE DENSITY) FORMAT
GAP
4a
40x
FF
PERPENDICULAR FORMAT
GAP
4a
80x
4E
SYN
C
12x
00
SYN
C
6x
00
SYN
C
12x
00
Note: If MT is set to “1” and the SC value is greater than the number of remaining formatted sectors
FORMAT A TRACK
The Format command allows an entire track to be formatted. After a pulse from the nINDEX pin is
detected, the FDC starts writing data on the disk including gaps, address marks, ID fields, and data
fields per the IBM System 34 or 3740 format (MFM or FM respectively). The particular values that will
be written to the gap and data field are controlled 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 FDC for C, H, R, and N (cylinder, head, sector number and sector
size respectively).
After formatting each sector, the host must send new values for C, H, R and N to the FDC for the next
sector on the track. The R value (sector number) 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
addresses (interleaving). This incrementing and formatting continues for the whole track until the FDC
encounters a pulse on the nINDEX pin again and it terminates the command.
Table 7.22 on page 70
sector and the number of sectors on each track. Actual values can vary due to drive electronics.
IAM
3
x
C
2
IAM
FC
IAM
3
x
C
2
F
C
F
C
on Side 0, verifying will continue on Side 1 of the disk.
GA
P1
50x
4E
GA
P1
26x
FF
GA
P1
50x
4E
SYN
C
12x
00
SYN
C
6x
00
SYN
C
12x
00
contains typical values for gap fields which are dependent upon the size of the
IDA
M
3
x
A
1
IDA
M
FE
IDA
M
3
x
A
1
F
E
F
E
DATASHEET
C
Y
L
C
Y
L
C
Y
L
H
D
H
D
H
D
S
E
C
S
E
C
S
E
C
69
N
O
N
O
N
O
C
R
C
C
R
C
C
R
C
GA
P2
22x
4E
GA
P2
11x
FF
GA
P2
41x
4E
SYN
C
12x
00
SYN
C
6x
00
SYN
C
12x
00
DAT
A
AM
3
x
A
1
DAT
A
AM
FB
or F8
DAT
A
AM
3
x
A
1
F
B
F
8
F
B
F
8
DA
TA
DA
TA
DA
TA
C
R
C
C
R
C
C
R
C
Rev 0.2 (09-28-04)
GA
P3
GA
P3
GA
P3
GAP
4b
GAP
4b
GAP
4b