Atmel SpW-10X user manual Rmw

			SpW-10X	Ref.:	UoD_SpW-10X_
			SpaceWire Router		UserManual
				Issue:	3.4
			User Manual
				Date:	11th July 2008
		Table 7-12 Read-Modify-Write Command Packet Fields
	Packet		Description			Bytes
	Field
Config Port		The configuration port address field routes the packet to the configuration				1
Address		port of the router. The configuration port address is always present when
		configuring the SpaceWire Router.
Destination		The destination logical address is not used in the SpaceWire Router. The				1
Logical		SpaceWire router accepts packets which have the default destination logical
Address		address of 254h (FEh).
Protocol		The RMAP protocol identifier is 01h.				1
Identifier
Command		The command byte indicates a read-modify-write command. The Source path				1
Byte		address length fields are set to the number of source path addresses
		required as defined in section 7.6.9.
Destination		The destination key identifier must match the contents of the destination key				1
Key		register, see section 9.5.10.
Source		The source path address field is used to add source path addresses to the				0,4,8,16
Path		head of the reply packet. The expected number of source path addresses is
Address		specified in the command byte. See section 7.6.9 for source path address
		decoding.
Source		The source logical address should be set to the logical address of the node				1
Logical		which sent the command.
Address
Transaction		The transaction identifier identifies the command packet and reply packet				2
Identifier		with a unique number.
Extended		The extended read address is not used in the SpaceWire router and shall				1
RMW		always be set to zero.
Address
RMW		The read-modify-write address identifies the SpaceWire router register				4
Address		address to modify. Valid RMW addresses are defined in section 9.
Data +		The data length of the read-modify-write command is 8, 4 bytes for data and				3
			Preliminary			67