formatting continues for the whole track until the FDC encounters a pulse on the IDX pin again and it terminates the
command.
Table 44 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 43 - FORMAT FIELDS
SYSTEM 34 (DOUBLE DENSITY) FORMAT
DATA
GAP4 SYN IAM GAP SYN IDAM C H S N C GAP SYN AM
C
a
C
1
C
Y D E O R
2
C
DAT R GAP GAP
80x
4E
12x
00
50x 12x
4E 00
L
C
C
22x 12x
4E 00
A
C
3
4b
3x FC
C2
3x FE
A
1
3x FB
A1 F8
SYSTEM 3740 (SINGLE DENSITY) FORMAT
DATA
GAP4 SYN IAM GAP SYN IDAM C H S N C GAP SYN AM
C
a
C
1
C
Y D E O R
2
C
DAT R GAP GAP
40x
FF
6x
00
26x
FF
6x
00
L
C
C
11x
FF
6x
00
A
C
3
4b
FC
FE
FB or
F8
PERPENDICULAR FORMAT
DATA
GAP4 SYN IAM GAP SYN IDAM C H S N C GAP SYN AM
C
a
80x
4E
C
12x
00
1
C
Y D E O R
2
C
DAT R GAP GAP
4b
50x 12x
4E 00
L
C
C
41x 12x
4E 00
A
C
3
3x FC
C2
3x FE
A
1
3x FB
A1 F8
SMSC DS – FDC37N769
Page 50 of 137
Rev. 02-16-07
DATASHEET
SMSC [ SMSC CORPORATION ]
