Fujitsu MPG3XXXAT Computer Drive User Manual


 
C141-E110-02EN
5 - 44
(20) READ BUFFER (X'E4')
The host system can read the current contents of the sector buffer of the device by issuing this
command. Upon receipt of this command, the device sets the BSY bit of Status register and sets
up the sector buffer for a read operation. Then the device sets the DRQ bit of Status register,
clears the BSY bit, and generates an interrupt. After that, the host system can read up to 512 bytes
of data from the buffer.
At command issuance (I/O registers setting contents)
1F7
H
(CM) 11100100
1F6
H
(DH)
×××
DV xx
1F5
H
(CH)
1F4
H
(CL)
1F3
H
(SN)
1F2
H
(SC)
1F1
H
(FR)
xx
xx
xx
xx
xx
At command completion (I/O registers contents to be read)
1F7
H
(ST) Status information
1F6
H
(DH)
×××
DV xx
1F5
H
(CH)
1F4
H
(CL)
1F3
H
(SN)
1F2
H
(SC)
1F1
H
(ER)
xx
xx
xx
xx
Error information
(21) WRITE BUFFER (X'E8')
The host system can overwrite the contents of the sector buffer of the device with a desired data
pattern by issuing this command. Upon receipt of this command, the device sets the BSY bit of
the Status register. Then the device sets the DRQ bit of Status register and clears the BSY bit
when the device is ready to receive the data. After that, 512 bytes of data is transferred from the
host and the device writes the data to the sector buffer, then generates an interrupt.
At command issuance (I/O registers setting contents)
1F7
H
(CM) 11101000
1F6
H
(DH)
×××
DV xx
1F5
H
(CH)
1F4
H
(CL)
1F3
H
(SN)
1F2
H
(SC)
1F1
H
(FR)
xx
xx
xx
xx
xx