Atmel SpaceWire Router SpW-10X User Manual
Ref.: UoD_SpW-10X_
UserManual
Issue: 3.4
SpW-10X
SpaceWire Router
User Manual
Date: 11
th
July 2008
Preliminary
24
The crossbar switch connects an input port to an output port allowing data to flow from the input port
to the output port. Several input ports may be connected simultaneously to several output ports all
passing data. Two or more input ports may not be connected to a single output port. The crossbar
switch is a “non-blocking” type because the connection of one input port to an output port does not
prevent another input port being connected to another output port at the same time. It is possible for
all eight input ports to be each connected to an output port so that all input ports and output ports are
being used.
to the output port. Several input ports may be connected simultaneously to several output ports all
passing data. Two or more input ports may not be connected to a single output port. The crossbar
switch is a “non-blocking” type because the connection of one input port to an output port does not
prevent another input port being connected to another output port at the same time. It is possible for
all eight input ports to be each connected to an output port so that all input ports and output ports are
being used.
3.6 TIME-CODE PROCESSING
An internal time-code register is used in the router to allow the router to be a time-code master or a
time-code slave.
time-code slave.
In master mode the time-code interface is used to provide a tick-in to the SpaceWire routing causing
time-codes to be propagated through the network. Two modes of time master operation are
supported, an automatic mode where a time-code is propagated on each external tick-in and a normal
mode where the time-code is propagated dependent on the external time-in signal.
time-codes to be propagated through the network. Two modes of time master operation are
supported, an automatic mode where a time-code is propagated on each external tick-in and a normal
mode where the time-code is propagated dependent on the external time-in signal.
In time-code slave mode a valid received time-code, one plus the value of the router time-code
register, causes a tick-out to be sent to the SpaceWire links and the external time-code interface. The
time-code is propagated to all time-code ports except the port on which the time-code was received. If
the time-code received is not one plus the value of the time-code register then the time-code register
is updated but the tick-out is not performed. In this way circular network paths do not cause a
constant stream of time-codes to be sent in a loop.
register, causes a tick-out to be sent to the SpaceWire links and the external time-code interface. The
time-code is propagated to all time-code ports except the port on which the time-code was received. If
the time-code received is not one plus the value of the time-code register then the time-code register
is updated but the tick-out is not performed. In this way circular network paths do not cause a
constant stream of time-codes to be sent in a loop.
3.7 CONTROL/STATUS REGISTERS
The control and status registers in the SpaceWire router provide the means to control the operation of
the router, set the router configuration and parameters or monitor the status of the device. The
registers are accessed using RMAP [AD2] command packets received by the configuration port.
the router, set the router configuration and parameters or monitor the status of the device. The
registers are accessed using RMAP [AD2] command packets received by the configuration port.