Atmel SpW-10X Manuel D’Utilisation

Ref.:   UoD_SpW-10X_ 

 

Issue:  3.4 

  

 

Date:  11

 

 

79

 

In this section the SpaceWire router control logic and operational modes are defined.  The router 
control logic determines how the SpaceWire link ports operate, how received packets are routed to 
their destination and how the timeout mechanism detects packet blockages in the router. 

8.1  SPACEWIRE LINK CONTROL 

Each of the eight SpaceWire links has an associated SpaceWire control register.  The register records 
status information from each link including link error information, link state and run status (see section 
9.4.3).   

The SpaceWire link control bits determine how the SpaceWire link operates.  The link control bits are 
Auto-start (default), Link-Start, Link-Disable and Deactivate.  The SpaceWire link data rate divider can 
also be set in the link control register. 

The following paragraphs define each of the link control functions 

8.1.1  Default operating mode 

The default operating mode is Auto-Start.  This is the mode setting for each link after power on or 
reset. 

8.1.2 Auto-Start  

In auto-start mode the SpaceWire port will remain inactive until a connection attempt is made by the 
SpaceWire device at the other end of the SpaceWire link.  The port will then start-up and make the 
connection 

The Auto-Start mode in conjunction with the automatic Link-Start and disable modes can help reduce 
power consumption by only activating SpaceWire links when packet data is transferred. See section 0. 

8.1.3 Link-Start 

The link-start control bit commands the SpaceWire port to try to make a connection with a SpaceWire 
device at the other end of the link.  Assuming a SpaceWire device is connected to the other end of the 
link the SpaceWire port will move to state Run.  Data transfer can take place when the link is started 
and the Link state is Run.