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Ref.:
SpaceWire CODEC IP
User Manual
UoD-Link-User
2.4
Issue: 27 March 2009
Date: Page: 63 / 69
(eq 3)
This relationship can be seen in Figure 10-4.
Figure 10-4 Latest Strobe Setup Time When no Skew
When data or strobe are skewed and jitter is added then the bit period T UI is adjusted accordingly.
When data is skewed the period is larger therefore T DSKEW is added to TUI. When strobe is skewed the
bit period TUI is smaller therefore TSSKEW is subtracted from TUI. Therefore eq. 3 becomes:
(eq 4)
Note when data is skewed then T SSKEW is zero and when strobe is skewed TDSKEW is zero for eq.4.
Figure 10-5 shows the data and strobe skew relationships.
Figure 10-5 Data and Strobe Skew effects on Strobe Setup Time
10.2.4
Minimum Pulse Width
The minimum pulse width of the data and strobe signals must be greater than the bit period. The
minimum pulse width of the SpaceWire receive clock with no skew is defined as the minimum of the
following.
(eq 5)
When data and strobe are skewed and jitter is added the minimum pulse with is defined as follows.
(eq 6)
(eq 7)
The timing parameters are shown in Figure 10-6.
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