Atmel SpW-10X user manual Read Modify Write Command, SpaceWire Router, User Manual, Preliminary

		SpW-10X	Ref.:	UoD_SpW-10X_
		SpaceWire Router		UserManual
			Issue:	3.4
		User Manual
			Date:	11th July 2008
Command	Read incrementing address reply command byte. The packet type bits in the				1
Byte	command byte indicate this packet is a reply packet.
Status	The command status is returned in this field. The command status can be				1
	command successful or an RMAP error code as defined in section 7.6.6.
Destination	The destination logical address is set to the default value FEh as the				1
logical	SpaceWire router does not have a logical address.
address
Transaction	The transaction identifier identifies the command packet and reply packet with a				2
Identifier	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.
Data	The data length field is the number of bytes read from the router as specified in				3
Length	the data length field of the command packet.
Header	The header CRC used to detect errors in the header part of the command				1
CRC	packet. See section 7.6.7 for CRC generation.
Data	The data read from the registers in the device. The data is returned in 32 bit				>=4
	words starting from the address specified in read address in the command
	packet.
Data CRC	The data CRC used to detect errors in the data part of the reply packet. See				1
	section 7.6.7 for CRC generation.

7.6.4 Read Modify Write Command

The read-modify-write command characteristics are defined in Table 7-8.

Table 7-11 Read-Modify-Write Command Characteristics

Action	Supported/	Maximum number
	Not Supported	of bytes
8-bit read-modify-write	NS	-
16-bit read-modify-write	NS	-

Non-aligned access accepted

-

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