DISK DRIVE OPERATION
Execution includes the transfer of one or more 512 byte (>512 bytes on Write Long) sectors of data from the drive to the host.
a)The host writes any required parameters to the Features, Sector Count, Sector Number, Cylinder and Drive/Head registers.
b)The host writes the command code to the Command register.
c)The drive sets DRQ when it is ready to accept the first sector of data.
d)The host writes one sector of data via the Data register.
e)The drive clears DRQ and sets BSY.
f)When the drive has completed processing of the sector, it clears BSY and asserts INTRQ. If transfer of another sector is required, the drive also sets DRQ.
g)After detecting INTRQ, the host reads the Status registers.
h)The drive clears the interrupt.
i)If transfer of another sector is required, the above sequence is repeated from (d).
6.6.2.1PIO Write Command
a)b)
Setup Issue Command
BSY=0
DRDY=1
BSY=1
Transfer Data
BSY=0
DRQ=1
BSY=1
DRQ=0
e)
Read | Transfer |
Status | Data |
BSY=0 |
|
DRQ=1 |
|
Assert | Negate |
INTRQ | INTRQ |
====
BSY=1
DRQ=0
e)
Read Status
BSY=0
Assert
INTRQ
Negate
INTRQ
6.6.2.2PIO Write Aborted Command
a)b) Setup Issue
Command
BSY=0
DRDY=1
BSY=1
e)
Read Status
BSY=0
Assert
INTRQ
Negate
INTRQ
SpinPoint V40 Product Manual | 85 |
