WM8321 datasheet(52/253 Pages) WOLFSON

52 / 253 page

WM8321

Production Data

PD, February 2012, Rev 4.0

Figure 19 ICE Memory Connection

Note that the WM8321 does not support programming the external ICE memory.

External programming of ICE whilst physically connected to the WM8321 is possible by putting the

WM8321 in the OFF state. This is supported on the evaluation board, provided the voltage levels on

SCLK2 and SDA2 are less than or equal to the LDO12 VPMIC voltage. Note that the Write-Protect

(WP) pin on the ICE must be connected to GND (Vss) in this case.

14.4 OTP / ICE MEMORY CONTROL

The OTP and ICE Memory commands are initiated by writing to the OTP Control Register, as defined

in Section 14.4.6. The supported commands are described below.

READ ICE MEMORY

- This command instructs the WM8321 to load data from the external ICE into

the WM8321 DCRW memory area. Note that this command is performed automatically when the

WM8321 starts up in development mode.

READ OTP MEMORY

- This command instructs the WM8321 to load data from the integrated OTP

memory area into the WM8321 DCRW memory area. Note that this command is performed

automatically when the WM8321 starts up in normal (ie. non-development) mode.

WRITE OTP MEMORY

- This command instructs the WM8321 to program the integrated OTP, by

writing a copy of the DCRW memory area (Pages 0, 1, 2 and 3) to the OTP memory. This command

should be performed after the required settings have been configured in the DCRW memory. The

required settings can be configured in the DCRW either as a result of a ICE Read command, or else

through register writes in the PROGRAM power state. Note that the Write OTP command should only

be performed once on each OTP page; after the Write OTP command has been performed, the

contents of the affected page(s) cannot be erased or re-programmed.

VERIFY OTP MEMORY

- This command instructs the WM8321 to compare the contents of the OTP

memory with the contents of the DCRW memory. The Verify OTP command performs a check that

the OTP data is identical to the DCRW contents, in order to confirm the success of the Write OTP

operation. For increased reliability, the WM8321 can apply a ‘Margin Read’ function when verifying

the OTP memory; it is recommended that the Margin Read option is used, as described in

Section 14.4.4.

FINALISE OTP PAGES

- This command instructs the WM8321 to set the OTP_CUST_FINAL bit in

the OTP memory. The Finalise OTP command ensures that any subsequent OTP_WRITE commands

to Page 2 or Page 3 of the OTP will have no effect and that the OTP contents are maintained

securely.

WM8321 Datenblatt(PDF) 52 Page - Wolfson Microelectronics plc