Ref.:
UoD_SpW-10X_
UserManual
Issue:
3.4
SpW-10X
SpaceWire Router
User Manual
Date:
11
th
July 2008
Preliminary
83
(
)
(
)
2
*
1
10
2
*
20
100
10
1
⎟
⎟
⎟
⎟
⎠
⎞
⎜
⎜
⎜
⎜
⎝
⎛
+
⎟
⎠
⎞
⎜
⎝
⎛
+
=
+
MbitDIV
TX
FEEDBDIV
MHz
MHz
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
FEEDB
D
IV
TXDIV
TX1
0
M
B
ITDIV
[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.