Atmel SpW-10X user manual SpaceWire Router, User Manual, Preliminary, Data CRC

SpW-10X	Ref.:	UoD_SpW-10X_
SpaceWire Router		UserManual
	Issue:	3.4
User Manual
	Date:	11th July 2008

In Figure 7-6 the format of the reply to a read incrementing address command is illustrated. The first byte sent by the SpaceWire router configuration logic is the port address followed by the destination logical address. Fields which are depicted in bold text are expected values. Fields which are shaded are optional. Note that the reply is always sent out of the same port as the command was received on. The Source Path Address should not include the output port of the router being commanded as the reply will be automatically sent out of the same port that the command arrived on. See section 7.6.8.

	First byte transmitted
	Source Path Address	Source Path Address	Source Path Address
Source Logical Address	Protocol Identifier	Packet Type, Command,	Status
	01h	Source Path Addr Len
Destination Logical Address	Transaction Identifier (MS)	Transaction Identifier (LS)	Reserved = 0
FEh
Data Length (MS)	Data Length	Data Length (LS)	Header CRC
00h
Data (Word 0 MSB)	Data	Data	Data (Word 0 LSB)
Data (Word 1 MSB)	Data	Data	Data (Word 1 LSB)
Data (Word n-1 MSB)	Data	Data	Data (Word n-1 LSB)
Data (Word n MSB)	Data	Data	Data (Word n LSB)

Data CRC

EOP

			Last byte transmitted
Bits in Packet Type / Command / Source Address Path Length Byte
MSB								LSB
0		0	0	0	1	1	Source Path	Source Path
							Address Length	Address Length
	Packet Type			Command			Source Path Address Length

Figure 7-6 Read Incrementing Address Reply Packet Format

Table 7-10 Read Incrementing Address Reply Packet Fields

Field	Description	Bytes
Source	Optional source path addresses specified in the command packet. If no source	0-12
Path	path addresses are specified then the first byte will be the source logical
Address	address.
Source	The source logical address specified in the command packet. If source path	1
Logical	addresses are not used then the source logical address is the address of the
Address	return packet.
Protocol	The RMAP protocol identifier value 01h.	1
Identifier
	Preliminary	64