wm8350 Wolfson Microelectronics plc, wm8350 Datasheet - Page 128

• Manufacturer Part Number: wm8350
• Description: Wolfson Audioplus? Stereo Codec With Power Management
• Manufacturer: Wolfson Microelectronics plc

WM8350
14.6 CONFIGURING THE DC-DC CONVERTERS
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The configuration of the DC-DC converters is described in the following sections. Some of the control
fields form part of the Custom Mode configuration settings and therefore will not require to be set in
software in some applications.
14.6.1
The DC-DC Converters can be enabled in software using the register fields defined in Table 70. All
DC-DC converters include a soft-start feature that helps to reduce the inductor current at start up. In
order to further reduce supply in-rush current, individual converters should be programmed to start in
different time slots within the start-up sequence.
In the WM8350 ACTIVE state, the DC-DC Converters can be enabled in software using the
DCn_ENA bits. Setting these bits whilst in the Pre-Active state (see Figure 65) will not immediately
enable the corresponding DC-DC converter; these bits will only become effective once the WM8350
has reached the ACTIVE state.
Each Converter may be programmed to switch on in a selected timeslot within the start-up sequence.
The WM8350 will set the DCn_ENA field for any DC-DC converter that is enabled during the start-up
sequence. Note that setting the DCn_ENSLOT fields in software is only relevant to the Development
Mode, as these fields are assigned preset values in each of the Custom Modes.
Each Converter may be programmed to switch off in a selected timeslot within the shutdown
sequence. If a Converter is not allocated to one of the 14 shutdown timeslots, it will be disabled when
the WM8350 enters the OFF state.
R13 (0Dh) or
R176 (B0h)
Note: These bits can be accessed through R13 or through R176. Reading from or writing to either
register location has the same effect.
R181 (B5h) for
DC-DC1
R184 (B8h) for
DC-DC2
R187 (BBh) for
DC-DC3
R190 (BEh) for
DC-DC4
R193 (C1h) for
DC-DC5
R196 (C4h) for
DC-DC6
Note: n is number between 1 and 6 that identifies the individual DC-DC converter
Table 70 Enabling and Disabling the DC-DC Converters
ADDRESS
DC-DC CONVERTER ENABLE
0,1,2,3
13:10
BIT
,4,5
9:6
DCn_ENA
DCn_ENSLO
T [3:0]
DCn_SDSLO
T [3:0]
LABEL
on CONFIG
on CONFIG
Dependant
Dependant
DEFAULT
settings
settings
0000
DCDCn converter enable
0 = disabled
1 = enabled
Note: internal conditions may prevent
the converter from actually switching on
- see DCDC/LDO Status register for
actual converter status.
Time slot for DC-DCn start-up
0000 = Disabled (do not start up)
0001 = Start-up in time slot 1
… (total 14 slots available)
1110 = Start-up in time slot 14
1111 = Start up on entering ACTIVE
Time slot for DC-DCn shutdown.
0000 = Shut down on entering OFF
0001 = Shutdown in time slot 1
…. (total 14 slots available)
1110 = Shutdown in time slot 14
1111 = Shut down on entering OFF
DESCRIPTION
PD, June 2009, Rev 4.1
Production Data
128