Chapter 7 Board-control Commands
Page 7 - 6 |
| Start Command List (01H) |
Start Command List (01H)
Command
Format
With this command you can instruct the RF3880 adapter to begin operating from a Command List. Since with Command List operation you can attain higher performance from your SCSI peripheral, this is one of the first commands you should issue to the adapter. It must be issued by means of a Single Command Structure.
See Chapter 4, Command Operation for information about using Command Lists.
The Parameter Block Format for the Start Command List command looks like this:
Address |
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| Byte Memory Address |
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Offset | Offset + 0 |
| Offset + 1 |
| Offset + 2 |
| Offset + 3 |
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00H |
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| Command Identifier |
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04H | Reserved |
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| Addr Mod |
| Adapter ID = FFH | |
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08H |
| Command List Memory Address | |||||
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0CH | Reserved |
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| Interrupt | ||
10H | Command = 01H |
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| Reserved |
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14H |
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| Reserved |
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18H |
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| Reserved |
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Description of Fields
Table 60: Start Command List Parameter Block
Each of the fields used by the Start Command List command are explained in the following section:
Command Identifier
The Command Identifier field is used to identify the Status Block associated with a Parameter Block. It must be a unique value.
Adapter ID
This field must always contain the ID of FFH to indicate a
Address Modifier
This is the value that the adapter is to drive onto the VMEbus Address Modifier Lines when selecting the memory address of the Command List.
Command List Memory Address
This field contains the address of the Command List in Memory. It points to the beginning of the structure: Parameter Block IN index.
21020285 D | User’s Guide |