Write Sector(S) Command Protocol - Fujitsu MPG3xxxAT Product Manual

a) The host writes any required parameters to the Features, Sector Count, Sector Number,
Cylinder, and Device/Head registers.
b) The host writes a command code in the Command register. The drive sets the BSY bit of the
Status register.
c) When the device is ready to receive the data of the first sector, the device sets DRQ bit and
clears BSY bit.
d) The host writes one sector of data through the Data register.
e) The device clears the DRQ bit and sets the BSY bit.
f) When the drive completes transferring the data of the sector, the device clears BSY bit and
asserts INTRQ signal. If transfer of another sector is requested, the drive sets the DRQ bit.
g) After detecting the INTRQ signal assertion, the host reads the Status register.
h) The device resets INTRQ (the interrupt signal).
i) If transfer of another sector is requested, steps d) and after are repeated.
Figure 5.4 shows an example of WRITE SECTOR(S) command protocol, and Figure 5.3 shows
an example protocol for command abort.
Command
Parameter write
~
b
a
BSY
DRDY
DRQ
INTRQ
Data transfer
Expanded
Command
DRQ
Max. 1 s
Data Reg. Selection
Data
IOR-
Word
IOCS16
Figure 5.4
Status read
f
c e
d d
0 1 2

WRITE SECTOR(S) command protocol

C141-E110-02EN
Status read
• • • •
g g
• • • •
h
• • •
• • • •
• • • •
• • • •
255
5 - 79