7 |
SCSI PACKETS
NOTES: There may be any number of scatter/gather entries.
The scatter/gather table must be in local MVME147 RAM (the DMA channel does not table walk offboard RAM).
Table address must be longword aligned.
Attach/Detach Packet (all devices)
For common command set refer to Appendix A. The following SCSI commands are executed during an attach:
| COMMAND | CONTROLLER |
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DEVICE | NAME | COMMAND | NOTES | |
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SCSI | Reserve device | $16 | Executed on attach if reserve- | |
Wincheste |
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r |
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| is set in packet. A reserve | |
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| device command is sent to the | |
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| controller. A reserve device | |
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| command can be used in a | |
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| ment to reserve the device. | |
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| Release device | $17 | Executed on detach if reserve- | |
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| is set in packet. A release | |
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| device command is sent to the | |
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| controller and the firmware | |
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| clears an internal attach flag. A | |
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| release device command can be | |
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| used in a | |
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| environment to release the | |
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| device. | |
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| Test unit ready | $00 | Checks whether the selected | |
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| device is ready. | |
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| Mode sense | $1A | To check the block size. If the | |
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| block size in the packet is | |
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| different than the | |
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| controller/drive setting, all | |
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| reads/writes are blocked and | |
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| an "attach error" is returned. | |
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