Atmel SpaceWire Router SpW-10X - Manual (Page 70)

Ref.: UoD_SpW-10X_
UserManual
Issue: 3.4
SpW-10X
SpaceWire Router
User Manual Date: 11 th
July 2008
Preliminary
70
logical address SpaceWire router does not have a logical address.
Transaction
Identifier
The transaction identifier identifies the command packet and reply packet
with a unique number. The transaction identifier in the reply packet is
copied from the command packet and returned in this field, so that the
command and the corresponding reply have the same transaction
identifier value.
2
Data Length The data length field is set to 4 bytes as 4 bytes are returned in the
Read-Modify-Write command.
3
Header CRC The header CRC used to detect errors in the header part of the
command packet. See section 7.6.7 for CRC generation.
1
Data The data read from the SpaceWire router registers before the modify
operation is performed.
4
Data CRC The data CRC used to detect errors in the data part of the reply packet.
See section 7.6.7 for CRC generation.
1
7.6.5 Write Command
The write command characteristics of the SpaceWire router are defined in Table 7-14.
Table 7-14 Write Command Characteristics
Action Supported/
Not Supported
Maximum number
of bytes Non-aligned access
accepted
8-bit write NS - -
16-bit write NS - -
32-bit write S 4 No
64-bit write NS - -
Word or byte address 32-bit aligned
Accepted Logical Addresses 0xFE
Accepted destination keys 0x20 at power on
Accepted address ranges 0x00 0000 0000 – 0x00 0000 0109
Incrementing address No