Atmel SpaceWire Router SpW-10X User Manual

Ref.:   UoD_SpW-10X_ 

 

Issue:  3.4 

  

 

Date:  11

 

 

69

 

In Figure 7-9 the format of the reply to a Read-Modify-Write command is illustrated. The first byte 
received 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. 

Source Path Address

Source Logical Address

Packet Type, Command,

Source Path Addr Len

Status

Transaction Identifier (MS)

Transaction Identifier (LS)

Header CRC

Data (MSB)

Data

Data

Data (LSB)

Source Path Address

Source Path Address

Data CRC

EOP

Bits in Packet Type / Command / Source Path Address Length Byte

MSB

Packet Type

Command

Source Path

Address Length

Source Path

Address Length

LSB

Source Path Address Length

 

 

Source Path 

Address  

Optional source path addresses specified in the command packet. If no 

source path addresses are specified then the first byte will be the source 

logical address. 

0-12 

Source Logical 

Address  

The source logical address specified in the command packet. If source 

path addresses are not used then the source logical address is the 

address of the return packet. 

1 

Protocol Identifier   The RMAP protocol identifier value 01h. 

1 

Command Byte  

Read-Modify-Write reply command byte. The packet type bits in the 

command byte indicate this packet is a response packet. 

1 

Status  

The command status is returned in this field. The command status can be 

command successful or an RMAP error code as defined in section 7.6.6. 

1 

Destination 

The destination logical address is set to the default value FEh as the 

1