Corp. SpaceWire Router User Manual

Ref.:
UoD_SpW-10X_
UserManual
Issue:
3.4
SpW-10X
SpaceWire Router
User Manual
Date:
11
th
July 2008
Preliminary
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MbitDIVTX
FEEDBDIVMHzMHz
MbitRate
TXDIV
To provide a SpaceWire signal with a nominal 50/50 duty cycle, TXRATE and TX10MbitDIV should be
even integers.
Not all values of FEEDBDIV, TXDIV and TXRATE give valid clock signals. Table 8-1shows the
recommended values to use to achieve a range of SpaceWire transmit data rates.
Table 8-1 Setting SpaceWire Transmit Data Rate
TXRATE
Initialisation
DataRate
0 1 2 3 4 5 6 7 8 9 10
FEEDBDIV
TXDIV
TX10MBITDIV
[1:1] [1:3] [1:1] [3:5] [1:1] [5:7] [1:1] [7:9] [1:1] [9:11] [1:1]
Data
Rate
Duty
Cycle
5 0 19 200.0 100.0 66.67 50.0 40.0 33.33 28.57 25.0 22.22 20.0 18.18 10.000 [19:21]
4 0 17 180.0 90.0 60.0 45.0 36.0 30.0 25.71 22.5 20.0 18.0 16.36 10.000 [17:19]
3 0 15 160.0 80.0 53.33 40.0 32.0 26.67 22.86 20.0 17.78 16.0 14.55 10.000 [15:17]
2 0 13 140.0 70.0 46.67 35.0 28.0 23.33 20.0 17.5 15.56 14.0 12.73 10.000 [13:15]
1 0 11 120.0 60.0 40.0 30.0 24.0 20.0 17.14 15.0 13.33 12.0 10.91 10.000 [11:13]
0 0 9 100.0 50.0 33.33 25.0 20.0 16.67 14.29 12.5 11.11 10.0 9.09 10.000 [9:11]
5 1 9 100.0 50.0 33.33 25.0 20.0 16.67 14.29 12.5 11.11 10.0 9.09 10.000 [9:11]
4 1 8 90.0 45.0 30.0 22.5 18.0 15.0 12.86 11.25 10.0 9.0 8.18 10.000 [1:1]
3 1 7 80.0 40.0 26.67 20.0 16.0 13.33 11.43 10.0 8.89 8.0 7.27 10.000 [7:9]
2 1 6 70.0 35.0 23.33 17.5 14.0 11.67 10.0 8.75 7.78 7.0 6.36 10.000 [1:1]
1 1 5 60.0 30.0 20.0 15.0 12.0 10.0 8.57 7.5 6.67 6.0 5.45 10.000 [5:7]
0 1 4 50.0 25.0 16.67 12.5 10.0 8.33 7.14 6.25 5.56 5.0 4.55 10.000 [1:1]
5 2 4 50.0 25.0 16.67 12.5 10.0 8.33 7.14 6.25 5.56 5.0 4.55 10.000 [1:1]
4 2 4 45.0 22.5 15.0 11.25 9.0 7.5 6.43 5.63 5.0 4.5 4.09 9.000 [1:1]
3 2 3 40.0 20.0 13.33 10.0 8.0 6.67 5.71 5.0 4.44 4.0 3.64 10.000 [3:5]
2 2 2 35.0 17.5 11.67 8.75 7.0 5.83 5.0 4.38 3.89 3.5 3.18 11.667 [1:1]
1 2 2 30.0 15.0 10.0 7.5 6.0 5.0 4.29 3.75 3.33 3.0 2.73 10.000 [1:1]
0 2 2 25.0 12.5 8.33 6.25 5.0  4.17 3.57 3.13 2.78 2.5 2.27 8.333 [1:1]
In Table 8-1 the values with a white background are the values that should be used. The ones in
red/shaded should not be used.
The first three columns give settings for the FEEDBDIV pins on the SpW-10X device, the TXDIV field
in the transmit clock register (see section 9.5.9) and the TX10MbitDIV field also in the transmit clock
register.