Production Data
WM8321
14 INSTANTCONFIG™ (ICE) AND OTP MEMORY CONTROL
14.1 GENERAL DESCRIPTION
The WM8321 is a highly configurable device which can be tailored specifically to the requirements of
a complex system application. The sequencing and voltage control of the integrated DC-DC
Converters and LDOs in power-up, shut-down and SLEEP conditions is crucial to the robust operation
of the application.
In development, the WM8321 allows designers to modify or experiment with different settings of the
control sequences by writing to the applicable registers in the OFF state prior to commanding an ‘ON’
state transition. Configuration settings can also be stored on an external EEPROM and loaded onto
the WM8321 as required, using the InstantConfig™ EEPROM (ICE) interface.
For production use, the WM8321 provides an on-chip One-Time Programmable (OTP) memory, in
which the essential parameters for starting up the device can be programmed. This allows the
WM8321 to start up and shut down the system with no dependency on any other devices for
application-specific configuration parameters.
14.2 ICE AND OTP MEMORY DEFINITION
An illustration of the WM8321 memory locations is shown in Figure 18. The main Register Map of the
WM8321 contains a block of data in a ‘Window’ area which is mirrored in the OTP and/or the ICE
Memory. Data from the external ICE Memory can be loaded into the Window area. Data can be
transferred from the Window into OTP Memory and also from the OTP Memory into the Window. The
Window is called the Device Configuration Register Window (DCRW); the data in this Window is
mirrored in other locations within the WM8321 Register Map.
Figure 18 ICE and OTP Memory Layout
The DCRW contains 5 pages of data, as illustrated in Figure 18.
PD, February 2012, Rev 4.0
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