Atmel SpaceWire Router SpW-10X - Manual (Page 63)

Ref.: UoD_SpW-10X_
UserManual
Issue: 3.4
SpW-10X
SpaceWire Router
User Manual Date: 11 th
July 2008
Preliminary
63
Destination
Key
The destination key identifier must match the contents of the destination key
register, see section 9.5.10.
1
Source
Path
Address
The source path address field is used to add source path addresses to the
head of the reply packet. The expected number of source path addresses is
specified in the command byte. See section 7.6.9 for source path address
decoding.
0,4,8,12
Source
Logical
Address
The source logical address should be set to the logical address of the node
which sent the command or it should be set to the default value of FEh.
1
Transaction
Identifier
The transaction identifier identifies the command packet and reply packet
with a unique number.
2
Extended
Read
Address
The extended read address is not used in the SpaceWire router and shall
always be set to zero.
1
Read
Address
The read address identifies the start address for the read incrementing
command. The valid starting read addresses are defined in section 9.
4
Data
Length
The data length defines the number of bytes to read from the router. Valid
data lengths are in the range 4-1064. 1064 allows the all the router registers
to be read in one command. If the data length field is not a multiple of four
bytes then the command is rejected by the SpaceWire router.
3
Header
CRC
The header CRC is the eight bit CRC code used to detect errors in the
command packet. The CRC code is checked before the command is
executed.
1