5.3 Host Commands
(20) WRITE LONG (X’32’ or X’33’)
This command operates similarly to the READ SECTOR(S) command except that the device writes the data and the ECC bytes transferred from the host system to the disk medium. The device does not generate ECC bytes by itself. The WRITE LONG command supports only single sector operation.
The number of ECC bytes to be transferred is fixed to 4 bytes and can not be changed by the SET FEATURES command.
This command is operated under the following conditions:
∙READ LONG issued → WRITE LONG (Same address) issues sequence (After READ LONG is issued, WRITE LONG can be issued consecutively.)
If above condition is not satisfied, the command operation is not guaranteed.
At command issuance (I/O registers setting contents)
1F7H(CM) | 0 | 0 | 1 | 1 | 0 | 0 | 1 | R |
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1F6H(DH) | × | L | × | DV | Head No. /LBA [MSB] | |||
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1F5H(CH) | Cylinder No. [MSB] / LBA |
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1F4H(CL) | Cylinder No. [LSB] / LBA |
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1F3H(SN) | Sector No. / LBA [LSB] |
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1F2H(SC) | 01 |
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1F1H(FR) | xx |
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At command completion (I/O registers contents to be read)
1F7H(ST) | Status information |
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1F6H(DH) | × |
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1F5H(CH) | Cylinder No. [MSB] / LBA | |||||
1F4H(CL) | Cylinder No. [LSB] / LBA | |||||
1F3H(SN) | Sector No. / LBA [LSB] | |||||
1F2H(SC) | 00 (*1) |
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1F1H(ER) | Error information |
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*1 If the command is terminated due to an error, this register indicates 01.
(21) 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
