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.

Parameter write

Command

Status read

Status read

~

b

 

 

 

a

f

g

• • • •

BSY

g

 

 

 

 

DRDY

c

e

 

 

 

 

 

DRQ

h

• • • •

INTRQ

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Data transfer

 

 

 

 

 

 

 

d

 

 

 

 

 

 

 

 

Expanded

 

 

 

 

 

 

 

 

Command

 

 

 

 

 

 

 

 

DRQ

 

 

Max. 1 μs

 

d

• • •

Data Reg. Selection

Data

IOR-

Word

0

1

IOCS16

• • • •

• • • •

• • • •

2255

Figure 5.4 WRITE SECTOR(S) command protocol

C141-E056-01EN

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Fujitsu MPC3065AH, MPC3045AH manual Write Sectors command protocol