CONTROL_MODULE Registers
9.3.55 vref_ctrl Register (offset = E14h) [reset = 0h]
vref_ctrl is shown in
and described in
Figure 9-58. vref_ctrl Register
31
30
29
28
27
26
25
24
Reserved
R-0h
23
22
21
20
19
18
17
16
Reserved
R-0h
15
14
13
12
11
10
9
8
Reserved
R-0h
7
6
5
4
3
2
1
0
Reserved
ddr_vref_ccap
ddr_vref_tap
ddr_vref_en
R-0h
R/W-0h
R/W-0h
R/W-0h
LEGEND: R/W = Read/Write; R = Read only; W1toCl = Write 1 to clear bit; -n = value after reset
Table 9-65. vref_ctrl Register Field Descriptions
Bit
Field
Type
Reset
Description
31-5
Reserved
R
0h
4-3
ddr_vref_ccap
R/W
0h
select for coupling cap for DDR
00 : No capacitor connected
01 : Capacitor between BIAS2 and VSS
10 : Capacitor between BIAS2 and VDDS
11: Capacitor between BIAS2 and VSS andamp
Capacitor between BIAS2 and VDDS
2-1
ddr_vref_tap
R/W
0h
select for int ref for DDR
00 : Pad/Bias2 connected to internal reference VDDS/2 for 2uA
current load
01 : Pad/Bias2 connected to internal reference VDDS/2 for 4uA
current load
10 : Pad/Bias2 connected to internal reference VDDS/2 for 6uA
current load
11 : Pad/Bias2 connected to internal reference VDDS/2 for 8uA
current load
0
ddr_vref_en
R/W
0h
active high internal reference enable for DDR
819
SPRUH73H – October 2011 – Revised April 2013
Control Module
Copyright © 2011–2013, Texas Instruments Incorporated