HOST SOFTWARE INTERFACE
CommandRegister
Contains code for the command to be performed. Additional command information should be written to the task file before the Command register is loaded. When this register is written, the BUSY bit in the Status register sets, and interrupt request to the host clears; invalid commands abort. (Detailed information on interface commands is given in Section 7.) Hex values for valid command formats follow:
Read Commands |
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Read Sector(s) | 20h | Normal reads; retries enabled | |
| 21h | Normal reads; retries disabled | |
| 22h | Read Long; retries enabled | |
| 23h | Read Long; retries disabled | |
Read Verify Sector(s) | 40h | Retries | enabled |
| 41h | Retries | disabled |
Read Sector Buffer | E4h |
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Read Multiple | C4h |
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Read DMA |
| C8h |
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| C9h | No retries | |
Write Commands |
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Write Sector(s) | 30h | Normal writes; retries enabled | |
| 31h | Normal writes; retries disabled | |
| 32h | Write Long; retries enabled | |
| 33h | Write Long; retries disabled | |
Write Verify Sector(s) | 3Ch |
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Write Sector Buffer | E8h |
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Write Multiple | C5h |
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Write DMA | CAh |
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| CBh | No retries | |
Mode Set/Check Commands |
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Set Features | EFh |
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Set Multiple Mode | C6h |
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Read Native Max Address | F8h |
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Set Max Mode | F9h |
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Power Mode Commands |
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Standby Immediate | 94/E0h | Stops drive spindle; do not change | |
Idle Immediate | 95/E1h | Starts spindle; do not change | |
Standby | 96/E2h | Stops spindle; change | |
Idle | 97/E3h | Starts spindle; change | |
Check Power Mode | 98/E5h |
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Set Sleep Mode | 99/E6h |
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Initialization Commands |
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Identify Drive | ECh |
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Initialize Drive Parameters | 91h |
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1xh |
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Seek, Format, and Diagnostic Commands |
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Seek | 7xh |
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Format Track | 50h |
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Execute Drive Diagnostic | 90h |
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S.M.A.R.T. Commands |
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Execute S.M.A.R.T. | B0h |
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