Atmel SpaceWire Router SpW-10X - Manual (Page 55)

Ref.: UoD_SpW-10X_
UserManual
Issue: 3.4
SpW-10X
SpaceWire Router
User Manual Date: 11 th
July 2008
Preliminary
55
7.5 DATA PACKETS
Packets which have addresses in the range 1 to 255 are routed to the SpaceWire ports and the
external ports dependent on the packet address. Data packets have an address header byte a cargo
field and an end of packet marker. The normal packet structure is show below.
ADDRESS
1-255
CARGO EOP/EEP
Figure 7-1 Normal router data packets
7.6 COMMAND PACKETS
Command packets are routed to the internal configuration port when the packet address is zero.
Command packets perform write and read operations to registers in the SpaceWire router. Command
packets accepted by the SpaceWire router are in the form shown in Figure 7-2.
Configuration read packets are in the form:
ADDRESS
0
COMMAND EOP
Figure 7-2 Command Packet Format
The SpaceWire router supports the Remote Memory Access Protocol (RMAP) [AD2] for configuration
of the internal router control registers and monitoring of the router status.
The following sections define the RMAP commands which are supported and the format of the RMAP
commands used by the SpaceWire Router.
7.6.1 Supported Commands
The RMAP Command set is listed in Table 7-4 and the supported RMAP commands are defined. The
commands which are not used are depicted with a grey background.