LPC47M14F-NC View Datasheet(PDF) - SMSC -> Microchip
Part Name
Description
MFG CO.
LPC47M14F-NC
SMSC -> Microchip
'LPC47M14F-NC' PDF : 205 Pages View PDF
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 25 contains typical values for gap fields that are dependent upon the size of the sector and the number of sectors
on each track. Actual values can vary due to drive electronics.
FORMAT FIELDS
SYSTEM 34 (DOUBLE DENSITY) FORMAT
DATA
GAP4a SYNC IAM GAP1 SYNC IDAM C H S N C GAP2 SYNC AM
C
80x 12x
50x 12x
Y D E O R 22x 12x
DATA R GAP3 GAP 4b
4E
00
4E 00
L
C
C 4E 00
C
3x FC
3x FE
3x FB
C2
A1
A1 F8
SYSTEM 3740 (SINGLE DENSITY) FORMAT
DATA
GAP4a SYNC IAM GAP1 SYNC IDAM C H S N C GAP2 SYNC AM
C
40x
6x
26x 6x
Y D E O R 11x 6x
DATA R GAP3 GAP 4b
FF
00
FF 00
L
C
C FF 00
C
FC
FE
FB or
F8
PERPENDICULAR FORMAT
DATA
GAP4a SYNC IAM GAP1 SYNC IDAM C H S N C GAP2 SYNC AM
C
80x 12x
50x 12x
Y D E O R 41x 12x
DATA R GAP3 GAP 4b
4E
00
4E 00
L
C
C 4E 00
C
3x FC
3x FE
3x FB
C2
A1
A1 F8
SMSC DS – LPC47M14X
Page 54
Rev. 05/02/2000
Share Link: 