DS125DF410_13 Datasheet, PDF (38/44 Pages) Texas Instruments – DS125DF410 Low Power Multi-Rate Quad Channel Retimer

DS125DF410
SNLS398E – JANUARY 2012 – REVISED MAY 2013
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Register (Hex)
4D
4E
4F
50
51
52
53
54
55
56
57
58
59
5A
5B
5C
5D
5E
5F
Table 14. CTLE Settings for Adaptation (continued)
Bits 7:6 (CTLE
Stage 0)
3
1
2
2
2
2
1
1
2
2
3
1
1
1
1
3
2
2
2
Bits 5:4 (CTLE
Stage 1)
0
2
1
0
0
2
0
1
0
3
0
1
1
2
3
1
1
1
2
Bits 3:2 (CTLE
Stage 2)
0
0
0
2
0
0
1
0
3
0
2
1
3
2
1
1
2
1
1
Bits 1:0 (CTLE
Stage 3)
0
0
0
0
2
0
2
2
0
0
0
3
1
1
1
1
1
2
1
CTLE Boost
String
3000
1200
2100
2020
2002
2200
1012
1102
2030
2300
3020
1113
1131
1221
1311
3111
2121
2112
2211
CTLE Adaptation
Index
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
As an alternative to, or in conjunction with, writing the CTLE boost setting registers 0x40 through 0x5f, it is
possible to set the starting CTLE boost setting index. To override the default setting, which is 0, set bit 3 of
register 0x2f. When this bit is set, the starting index for adaptation comes from register 0x39, bits 4:0. This is the
index into the CTLE settings table in registers 0x40 through 0x5f. When this starting index is 0, which is the
default, CTLE adaptation starts at the first setting in the table, the one in register 0x40, and continues until the
optimum FOM is reached.
Setting the Output Differential Voltage
Register 0x2d, bits 2:0
There are eight levels of output differential voltage available in the DS125DF410, from 0.6 V to 1.3 V in 0.1 V
increments. The values drv_sel_vod[2:0] in bits 2:0 of register 0x2d set the output VOD. The available VOD
settings and the corresponding values of this bit field are shown in Table 15.
Bit 2, drv_sel_vod[2]
0
0
0
0
1
1
1
1
Table 15. VOD Settings
Bit 1, drv_sel_vod[1]
Bit 0, drv_sel_vod[0]
0
0
0
1
1
0
1
1
0
0
0
1
1
0
1
1
Selected VOD (V, peak-to-peak,
differential)
0.6
0.7
0.8
0.9
1.0
1.1
1.2
1.3
38
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