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GR716-DS-UM, May 2019, Version 1.29
526
www.cobham.com/gaisler
GR716
52.11.2 External SpaceWire clock timing
The timing waveforms are shown in figure 96, and the timing parameters are defined in table 694.
52.11.3 External 1553B clock timing
The timing waveforms are shown in figure 96, and the timing parameters are defined in table 694.
Table 694.
External SpaceWire clock timing parameters
Name
Parameter
Reference edge
Min
Max
Unit
t
SPWCLK
0
Clock period
1)
-
10
-
ns
Clock period
2) 3)
-
40
200
ns
t
SPWCLK
1
Clock high/low pulse length
1)
-
0.45 x t
SP-
WCLK0
0.55 x t
SP-
WCLK0
ns
Clock high/low pulse length
2)
-
0.40 x t
SP-
WCLK0
0.60 x t
SP-
WCLK0
ns
t
SPWCLK
2
Clock cycle jitter
1)
-
-100
100
ps
Clock cycle jitter
2)
-
-
2
ns
Note 1:
Only applicable when PLL is bypassed (see section 4).
Note 2:
Only applicable when PLL use SPWCLK to generate internal SpaceWire clock (see section 4)
Note 3:
When SpaceWire clock is used as source to the PLL the internal SpaceWire clock shall not exceed
100MHz
Table 695.
External 1553B clock timing parameters
Name
Parameter
Reference edge
Min
Max
Unit
t
1553CLK0
Clock period
-
50
50
ns
t
1553CLK
1
Clock high/low pulse length
-
25
25
ns
Note 1:
External MIL-1553B clock is only available via IO mux, see chapter 2.5
Figure 96.
External SpaceWire clock timing waveforms
SPWCLK
t
SPWCLK1
t
SPWCLK0
t
SPWCLK1
Figure 97.
External 1553B clock timing waveforms
1553_CLK
t
1553CLK1
t
1553CLK0
t
1553CLK1