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SpaceWire Router
UserManual
Issue: 3.4
User Manual | Date: 11th July 2008 |
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Figure 7-12 and Figure 7-13 illustrate how source path addresses are returned in relation to the RMAP packet description.
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Dest Logical | Protocol ID | Command | Dest Key |
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00 | 00 | 04 | 02 |
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Source Logical | Trans ID(1) | Trans ID(0) | Address(4) |
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Figure 7-12 Source Path Address field decoding
| Local Source | 04 | 02 |
| Path Address | ||
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Source Logical | Protocol ID | Command | Status |
Figure 7-13 Source Path Addresses in Reply Packet
7.6.10 Command Packet Fill Bytes
The Configuration port accepts packets which are addressed to port 0. In the RMAP command the next byte after the destination address 0 is the destination logical address byte (which in the router is expected to be the default 254 value). The format is shown in Figure
Path
Address
0
Dest
Logical Protocol ID
Address 1
254
RMAP Header
Figure 7-14 Normal Configuration Packet Header Structure
To allow source nodes which have a 16, 24 or 32 bit access port then the configuration port accepts up to three null bytes at the start of the packet. The null bytes must be zero otherwise they will be treated as the destination logical address and an invalid destination logical address shall be recorded if the byte is not 254. The header with fill bytes is shown in the Figure
Path
Address
0
Fill Byte
0
Fill Byte
0
Fill Byte
0
Dest
Logical
Address
254
Protocol ID
1
RMAP Header
Figure 7-15 Fill Bytes Configuration Header Structure
Note that the command packet fill bytes feature is specific to the
Preliminary | 78 |