Scanner Interface
The normal MODE SENSE (6) sequence for the scanner is as follows:
Step | Bus phase | Initiator operation | ← → | Target operation |
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1 | Bus Free | Checks Bus Free |
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2 | (Arbitration) | Acquires the bus use |
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3 | Selection | Selects the target | → |
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| Drives the BSY signal |
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4 | (Message Out) | Selects the logical | → |
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5 | Command | Specifies MODE | → |
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| SENSE (6) (CDB) |
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6 | Data In | Specifies MODE | → | Reports mode data |
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| SENSE parameter |
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| data |
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7 | Status |
| ← | Reports the GOOD status |
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8 | Message In |
| ← | Reports message |
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| (Command complete) |
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| Releases the BSY signal |
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9 | Bus Free |
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(1)MODE SENSE (6) command: Command phase (Initiator to Target)
The MODE SENSE (6) command is used for the target to report mode parameters to the initiator. The command descriptor block (CDB) is as follows:
7 | 6 |
| 5 | 4 | 3 |
| 2 | 1 | 0 | ||
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Byte 0 |
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| Operation code X’1A’ |
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1 |
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| Logical unit number |
| Reserved | DBD |
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| Reserved |
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2 |
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| PC |
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| Page code |
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3 |
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| Reserved |
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4 |
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| Allocation length |
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5 |
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| Control byte |
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Appendix