6.Command Specification | MODE SELECT |
6.7.1.Disconnect-Reconnect Page (02h)
The drive supports the
Table
Bit | 7 | 6 | 5 |
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| 2 | 1 |
| 0 |
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0 | PS(0) | Reserved |
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| Page Code (02h) |
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1 |
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| Page Length (0Eh) |
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2 |
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| Buffer Full Ratio (00h) |
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3 |
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| Buffer Empty Ratio (00h) |
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4 | (MSB) |
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| Bus Inactivity Limit (00h) |
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5 |
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6 | (MSB) |
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| Disconnect Time Limit (0000h) |
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7 |
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8 | (MSB) |
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| Connect Time Limit (00h) |
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9 |
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10 | (MSB) |
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| Maximum Burst Size (4000h) |
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11 |
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12 | Reserved | Fair Arbitration (00b) |
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13 |
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| Reserved |
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14 |
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| Reserved |
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15 |
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| Reserved |
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Buffer Full Ratio, Buffer Empty Ratio, Bus Inactivity Limit and Connect Time Limit fields are not supported by the drive if set to
Disconnect Time Limit: This field indicates the minimum time in 100 microsecond increments that the drive will wait after releasing the SCSI bus before attempting
Maximum Burst Size: This field defines the maximum amount of data that the drive will transfer during a data phase before disconnecting. This value is expressed in increments of 512 bytes. This is
Note: 512 (200h) ⋅ 16384 (4000h) = 8388608(8 Mbytes) which means that the Maximum Burst Size is approximately equal to
FAIR ARBITRATION: This field indicates whether the drive will use fair or unfair arbitration when requesting an interconnect tenancy. Setting this field to 1 will enable the SCSI Bus Fairness protocol. Setting this field to zero will disable it. The drive determines fairness by monitoring prior arbitration attempts by other SCSI devices. It will postpone arbitration for itself until all lower priority SCSI devices that previously lost arbitration either win a subsequent arbitration or discontinue their arbitration attempts. It will monitor the arbitration attempts of the other SCSI devices and refresh the fairness register with the SCSI ID’s of any lower priority SCSI devices that lost arbitration. This field is not support.
DTDC: This field defines further restrictions on when a disconnect is permitted.
DTDC | Description |
00b | Data transfer disconnect control is not used. Disconnect is controlled by the other field in this |
| page. |
01b | A target will not attempt to disconnect once the data transfer of a command has started until all |
| data the command is to transfer has been transferred. The connect time limit and bus inactivity |
| limit are ignored during the data transfer. |
10b | Reserved |
11b | A target will not attempt to disconnect once the data transfer of a command has started until |
| the command is complete. The connect time limit and bus inactivity limit are ignored once data |
| transfer has started. |
SONY |
