Atmel SpaceWire Router SpW-10X User Manual

Ref.:   UoD_SpW-10X_ 

 

Issue:  3.4 

  

 

Date:  11

 

 

66

 

32-bit read-modify-write 

S 

4 

No 

64-bit read-modify-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 

 

The RMAP read-modify-write command is supported by the SpaceWire router. The read modify write 
command is used to set or reset a single or number of bits in a router register. The Read-Modify-Write 
command is useful when it is desirable to set a link register setting without upsetting the other settings 
in one command, i.e. set the start bit without modifying the data rate.  

In Figure 7-7 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. 

Packet Type, Command

Source Path Addr Len

Destination Key

Source Path Address

Source Path Address

Source Path Address

Source Path Address

Source Logical Address

Transaction Identifier (MS)

Transaction Identifier (LS)

RMW Address

RMW Address (LS)

Header CRC

Data (MS)

Data

Data

Data (LS)

Data/Mask CRC

EOP

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

MSB

Packet Type

Command

Mask (MS)

Mask

Mask

Mask (LS)

Source Path

Address Length

Source Path

Address Length

LSB

Source Path Address Length