GM82C803CN Datasheet, PDF (45/84 Pages) List of Unclassifed Manufacturers – 2.88 MB FDC/ Dual UARTs with FIFO/PIO(EPP/ ECP)/ IDE Interface/ S-IR/ PnP

GM82C803CN
PARAMETER ABBREVIATIONS
C
D0-3
D
DIR
DS1,0
Cylinder Number. The currently selected cylinder number 0 through 225.
Drive Select 0-3. Designates which drives are perpendicular drives, a 1 indicating perpendicular drive.
Data. The pattern to be written in each sector data field during formal
Direction. If this bit is 0, then the head will step out from the inside during a relative seek. If set to 1,
the head will ^{step in toward inside.}
Disk Drive Select
DS1 DS0
00
01
10
11
Disk Drive
drive 0
drive 1
drive 2
drive 3
DTL Data Length. When N is defined as 00(hex), DTL stands for the Data length which users are going to read out or
write into the sector. When N is not zero, DTL has no meaning and should be set to FF(hex).
EC Enable Count. When this bit is 1, the DTL parameter of the verify command becomes SC (Number of sectors per
track).
EFIFO Enable FIFO. When this bit is 0, the FIFO is enabled. A 1 pulse the FDC in the NEC765 compatible mode where
the FIFO is disabled.
EIS Enable implied seek. when this bit is 1, a seek operation will be performed before executing any read or write co-
mmand that requires the C parameter in the command phase. A 0 disables the implied seek.
EOT End of track. The final sector number on a cylinder.
GAP Alters Gap2 length when using perpendicular mode.
GPL Gap Length. The Gap3 size. During the Format command, it determines the size of Gap3.
H/HS Head Address.. It stands for head number 0 to 1, as specified in ID field.
HLT Head Load Time. The time interval that FDC waits after loading the head and before initiating a read or write op-
eration. See specify command.
HUT Head Unload Time. The time interval from the end of the execution phase of a Read or Write command until the
head is unloaded. See specify command.
Lock It defines whether EFIFO, FIFOTHR, and PRETRK parameters of the Configure command can be reset to their
default values by a software reset. See LOCK command.
MF FM or MFM. IF FM is 0, FM mode is selected. IF it is 1, MFM selected.
MT Multitrack. If MT is 1 after finishing Read/Write operation on side 0, FDC will automatically start searching for s-
ector 1 0n side 1.
N N stands for the number of bytes written in a sector. if N is 00, then the sector size is 128 bytes. The number of by-
tes transferred is determined by DTL. Otherwise the sector size is (2 raised to the N’th power) times 128. All values
up to 07(hex) are allowable.
N
Sector size
00
128 bytes
01
256 bytes
02
512 bytes
03
1024 bytes
---
07
16 bytes