5.3 Host Commands
(19) READ LONG (X’22’ or X’23’)
This command operates similarly to the READ SECTOR(S) command except that the device transfers the data in the requested sector and the ECC bytes to the host system. The ECC error correction is not performed for this command. This command is used for checking ECC function by combining with the WRITE LONG command.
Number of ECC bytes to be transferred is fixed to 4 bytes and cannot be changed by the SET FEATURES command.
The READ LONG command supports only single sector operation.
At command issuance (I/O registers setting contents)
1F7H(CM) | 0 | 0 | 1 | 0 | 0 | 0 | 1 | R |
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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R= 0 →with Retry R = 1 →without Retry
At command completion (I/O registers contents to be read)
1F7H(ST) | Status information |
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1F6H(DH) | × |
| L | × | DV | Head No. /LBA [MSB] |
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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.
