Atmel SpW-10X Data Strobe Disable Waveform, Reset Anomaly Workarounds, SpaceWire Router

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

13.3.2 Data Strobe Disable Waveform

If a SpaceWire link is disabled, either by configuration command or a disconnect, parity, escape or credit error, the final bit of strobe will be extended to a 100 ns period pulse. No simultaneous transitions or glitches can occur during a disable operation. This operation is as expected. The reset anomaly has no effect on link disconnect operation.

The output waveforms during link disconnect are shown in Figure 13-5.

Figure 13-5 Link Disconnect Waveforms

13.3.3 Reset Anomaly Workarounds

The reset anomaly will not cause any problem when operating with any SpaceWire compliant device [AD1].

When operating with IEEE-1355 devices like the old SMCS332 and SMCS116 devices it is recommended that the old devices are replaced by the new SpaceWire compliant SMCS332SpW and SMCS116SpW devices, which are or shortly will be available from Atmel.

If operation with legacy units which use IEEE-1355 devices is necessary and these devices cannot be replaced by the new SpaceWire compliant parts, then the following reset sequence is recommended:

1.Assert the reset for the SpW-10X device.

2.Assert the reset for any IEEE-1355 devices attached to the SpW-10X device.

3.Release the reset of the SpW-10X device.

4.Wait for at least 10 µs.

5.Release the reset of the IEEE-1355 devices.

Alternatively when only a reset of the SpW-10 is required and an attached IEEE-1355 device is not to be reset at the same time, then the following reset sequence is recommended:

1.Send configuration commands to the SpW-10X device to disable the ports attached to IEEE-1355 devices.

2.Once all these ports have been disabled, wait for at least 10 µs.

3.Assert the reset for the SpW-10X device.

4.Release the reset of the SpW-10X device.

Preliminary 147