wm8400 Wolfson Microelectronics plc, wm8400 Datasheet - Page 137

• Manufacturer Part Number: wm8400
• Description: Wolfson Audioplustm Hi-fi Audio Codec And Power Management Unit For Mobile Multimedia
• Manufacturer: Wolfson Microelectronics plc

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Pre-Production
CONFIGURING THE DC-DC CONVERTERS AND LDO REGULATORS
OPERATING MODE CONTROL
The operating mode may be selected in software using the PWR_STATE register field, as defined in
Table 80.
The operating mode may also be selected by a logic level applied to MSLEEP (referenced to
MBVDD) or HSLEEP (referenced to HBVDD). By default, these inputs are active high. The polarity of
these pins may be inverted using the DSLEEP1_POL and DSLEEP2_POL register fields. When
MSLEEP or HSLEEP is asserted, this takes precedence over the PWR_STATE setting, and places
the WM8400 in Deep Sleep mode.
In summary, the Deep Sleep state may be entered in three ways: (1) Asserting MSLEEP, or (2)
Asserting HSLEEP, or (3) Setting PWR_STATE = 10.
Table 80 WM8400 Power State Control
ENABLING THE CONVERTERS
The DC-DC converters and the LDO regulators can be enabled in software using register fields as
defined in Table 81.
Table 81 DC-DC Converter and LDO Regulator Software Enable
R76 (4Ch)
R65 (41h)
R66 (42h)
R67 (43h)
R68 (44h)
R70 (46h)
R72 (48h)
REGISTER
REGISTER
ADDRESS
ADDRESS
BIT
1:0
BIT
15
15
15
15
15
15
3
2
DSLEEP1_POL
DSLEEP2_POL
PWR_STATE
LDO1_ENA
LDO2_ENA
LDO3_ENA
LDO4_ENA
DC1_ENA
DC2_ENA
LABEL
LABEL
DEFAULT
DEFAULT
0b
0b
0b
0b
0b
0b
00
0
0
LDO1 Software enable
0 = Disabled
1 = Enabled
LDO2 Software enable
0 = Disabled
1 = Enabled
LDO3 Software enable
0 = Disabled
1 = Enabled
LDO4 Software enable
0 = Disabled
1 = Enabled
DC1 Software enable
0 = Disabled
1 = Enabled
DC2 Software enable
0 = Disabled
1 = Enabled
MSLEEP control
0 = Active high
1 = Active low
HSLEEP control
0 = Active high
1 = Active low
Power State software control
00 = Active
01 = Soft Sleep
10 = Deep Sleep
11 = Reserved
DESCRIPTION
DESCRIPTION
PP, April 2009, Rev 3.0
WM8400
137