Host Interface
4.3.5 MODE SENSE command
Table 4.31 MODE SENSE command
Bit | 7 |
| 6 |
| 5 |
| 4 |
| 3 |
| 2 | 1 | 0 |
Byte |
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0 |
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| Operation Code (1Ah) |
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1 |
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| Reserved |
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| DBD |
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| Reserved |
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2 | 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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| Reserved |
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The MODE SENSE command transfers a mode parameter list to INIT.
If Disable Block Descriptor (DBD) is 1, the command does not return a block descriptor. If DBD is 0, the command returns a block descriptor.
Allocation Length specifies the number of bytes of the mode parameter to be transferred. If Allocation Length is 0, the command ends normally without transferring any data.
Page Control (PC) specifies the type of page to be sent.
| Table 4.32 | Page control field | |
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Bit 7 | Bit 6 |
| Parameter type |
0 | 0 |
| Current value |
0 | 1 |
| Variable value |
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1 | 0 |
| Default value |
1 | 1 |
| Saved value |
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Page Code specifies a mode page to be transferred. If Page Code is 3Fh, all mode pages are transferred. Table 4.10, "Mode page codes" lists the mode pages that are supported.
Mode pages are transferred in ascending order of page code.
If 0 is specified for both Page Code and Page Control, the command transfers Mode Parameter Header and Block Descriptor (only if the DBD bit is 0).
Table 4.33 is a list of mode parameters.
