We are using CYW43438, and I want to know what content should be burned to the OTP while manufacturing.
I searched google and only found the application note - OTP Programming and NVRAM Development in SDIO Mode
It describes how to create and burn a CIS structure to OTP by using command wl cisdump or dump by wl cisdump.
But when I dump the whole OTP using the command wl otpdump, I found that CIS structure was just a part of the whole OTP content, there are more content before and after it which was NOT described in the document above (see below which dumped from CYW43362).
Are there any more documents describe about it ?
Thanks.
Hello,
The OTP contains some module specific information which is used by the board after reset. The user programmable memory starts from the OTP header info:
Post SDIO header, the board parameters can be entered as mentioned in the App note. Note that all the customizable parameters are mentioned in the nvram file specific to a board. Once the parameters are hardened, selected parameters are written to OTP as it is not big enough to contain all nvram parameters. Also the CIS tuples are not defined for all the nvram parameters.
Module vendors populate the OTP to contains SDIO header, board rev, board type, WLAN MAC addr, sromrev, Module vendor specific ID, OTP end, etc.
ciswrite is used to write specific bits to OTP. cisdump is used to confirm whether the OTP is programmed successfully. If the cisdump is verified to match the OTP binary map(wl otpdump), the OTP programming is complete.