FDC37M604 datasheet(38/182 Pages) SMSC

38 / 182 page

Table 19 - Description of Command Symbols

SYMBOL

NAME

DESCRIPTION

NCN

New Cylinder

Number

The desired cylinder number.

Non-DMA Mode

Flag

When set to “1”, indicates that the FDC is to operate in the non-

DMA mode. In this mode, the host is interrupted for each data

transfer.

When set to “0”, the FDC operates in DMA mode,

interfacing to a DMA controller by means of the DRQ and nDACK

signals.

Overwrite

The bits D0-D3 of the Perpendicular Mode Command can only be

modified if OW is set to “1”. OW id defined in the Lock command.

PCN

Present Cylinder

Number

The current position of the head at the completion of Sense

Interrupt Status command.

POLL

Polling Disable

When set, the internal polling routine is disabled.

When clear,

polling is enabled.

PRETRK

Precompensation

Start Track

Number

Programmable from track 00 to FFH.

Sector Address

The sector number to be read or written. In multi-sector transfers,

this parameter specifies the sector number of the first sector to be

read or written.

RCN

Relative Cylinder

Number

Relative cylinder offset from present cylinder as used by the

Relative Seek command.

Number of

Sectors Per Track

The number of sectors per track to be initialized by the Format

command. The number of sectors per track to be verified during a

Verify command when EC is set.

Skip Flag

When set to “1”, sectors containing a deleted data address mark

will automatically be skipped during the execution of Read Data. If

Read Deleted is executed, only sectors with a deleted address

mark will be accessed.

When set to "0", the sector is read or

written the same as the read and write commands.

SRT

Step Rate Interval The time interval between step pulses issued by the FDC.

Programmable from 0.5 to 8 milliseconds in increments of 0.5 ms

at the 1 Mbit data rate. Refer to the SPECIFY command for actual

delays.

ST0

ST1

ST2

ST3

Status 0

Status 1

Status 2

Status 3

Registers within the FDC which store status information after a

command has been executed. This status information is available

to the host during the result phase after command execution.

FDC37M604 Datasheet(PDF) 38 Page - SMSC Corporation

FDC37M604 Datasheet(HTML) 38 Page - SMSC Corporation

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 ...More

Datasheet Download

Link URL