Atmel SpW-10X Spacewire Router Packet Types, Packet Addresses, SpaceWire Router, User Manual

SpW-10X	Ref.:	UoD_SpW-10X_
SpaceWire Router		UserManual
	Issue:	3.4
User Manual
	Date:	11th July 2008

7. SPACEWIRE ROUTER PACKET TYPES

This section describes how the routing control logic interprets packets.

7.1 PACKET ADDRESSES

The routing control logic interprets the first byte of each received packet as the packet address. The packet address defines the physical ports through which the routing control logic will use to route the packet towards its destination.

Packets which have a path address (0-31) as the first byte are always routed to the corresponding physical port number on the router. Packets which have a logical address (32-255) are routed to physical ports dependent on the contents of the routing table. The internal SpaceWire router routing table can be set up to assign logical addresses to the physical ports, except the configuration port (port 0) which can only be accessed by path addressing

The physical port addresses for the SpaceWire router and the expected packet type is defined in the table below. The packet types can be viewed in section 0.

Table 7-1 Packet Address Mapping

Packet Address	Expected Packet Type	Physical Port type
0	Command packet	Configuration port
1	Any type	SpaceWire link port 1
2	Any type	SpaceWire link port 2
3	Any type	SpaceWire link port 3
4	Any type	SpaceWire link port 4
5	Any type	SpaceWire link port 5
6	Any type	SpaceWire link port 6
7	Any type	SpaceWire link port 7
8	Any type	SpaceWire link port 8
9	Any type	External FIFO port 1
10	Any type	External FIFO port 2
11-31	N/A	Invalid addresses
32-255	Any type	Logical addresses

Note that logical address 255 is reserved in the SpaceWire standard [AD1].

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