Production Data
WM8321
The OTP and ICE Memory commands are each described in the following sections. Note that, in
some cases, commands may be executed on a single page of memory or may be executed as a Bulk
operation on all available memory pages.
Completion of each OTP or ICE Memory command is indicated via an Interrupt flag, as described in
Section 14.5. The pass/fail outcome of any OTP command is also indicated by the Interrupt bits. Note
that read/write access to the WM8321 Register Map is not supported while a ICE/OTP command is in
progress. It is recommended that the I¯R¯Q¯ pin is configured to indicate any ICE/OTP Interrupt event;
the host processor should read the OTP/ICE Interrupt event flags to confirm the OTP/ICE command
status following the assertion of the I¯R¯Q¯ pin.
The programming supply voltage PROGVDD is required for the OTP Write commands and the OTP
Finalise command. It is also necessary to overdrive the LDO12VOUT pin from an external supply.
See Section 6 for details of the required supply voltages.
14.4.1 ENTERING / EXITING THE PROGRAM STATE
The ICE and OTP commands are only supported when the WM8321 is in the PROGRAM state. The
WM8321 can only enter the PROGRAM state as a transition from the OFF state. This is commanded
by setting the OTP_PROG register bit.
Important note - when the PROGRAM state is selected, the WM8321 will read all pages of the OTP
memory into the corresponding pages of the DCRW. This is required in order to confirm if the OTP
contents have already been finalised (see Section 14.4.5). The previous contents of the DCRW
registers will be lost when the PROGRAM state is entered.
The transition into the PROGRAM state can be confirmed by reading the MAIN_STATE register field
as defined in Section 11.2. When the MAIN_STATE register reads back a value of 01011, then the
WM8321 is in the PROGRAM state.
In the PROGRAM state, the ICE and OTP commands are initiated by further writes to the OTP
Control Register (R16394), as described in the following sections.
To exit the PROGRAM state and resume normal operations, a Device Reset must be scheduled.
14.4.2 OTP / ICE READ COMMAND
The Read command loads either one or all data pages from the ICE or OTP into the corresponding
page(s) of the DCRW. The Read commands are selected by writing 1 to the OTP_READ bit.
To read the OTP, the OTP_MEM bit should be set to 1. To read the ICE, the OTP_MEM bit should be
set to 0.
The Read Margin Level is selected by setting the OTP_READ_LVL. Note that this register relates to
the OTP only; it has no effect on ICE Read commands. The recommended setting for the OTP Read
command is ‘Normal’ level. The OTP_READ_LVL field should be set to 00b.
To read a single memory page, the applicable page is selected by setting the OTP_PAGE field. To
read all memory pages, the OTP_BULK bit should be set to 1.
Note that the OTP_PAGE field is defined differently for ICE pages and for OTP pages, as detailed in
Section 14.4.6.
All other bits in the OTP Control Register should be set to 0 when a Read command is issued. (Note
that OTP_PROG should be set to 0 when a Read command is issued.)
For typical applications, the Bulk Read commands are recommended. The OTP Control Register
contents for the OTP / ICE Bulk Read Commands are detailed in Table 20.
READ COMMAND
ICE Read All
OTP CONTROL REGISTER VALUE
0120h
2120h
OTP Read All
Table 20 OTP / ICE Read Command
PD, February 2012, Rev 4.0
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WOLFSON [ WOLFSON MICROELECTRONICS PLC ]
