topic Re: lpc55sxx DFLT and PIN setting clarification in LPC Microcontrollers

lpc55sxx DFLT and PIN setting clarification

DWightman — Thu, 10 Nov 2022 20:20:35 GMT

The AN13037 description of the DFLT / PIN configuration seems to conflict with the user manual

It says

and

I interpret this to mean that setting the DFLT / PIN to 1/1 gives access to the specific sub-domain and that a CFPA cannot set a lower restriction level to a subdomain than what was set in the CMPA.

However, the User Manual on page 975 says that a DFLT / PIN setting of 1 / 1 has the highest restriction level and disables access to a submodule. I also assume that if the CMPA configures one of the submodules as 1/1, then the CFPA wouldnt be able to set it to a lower configuration.

It would be very nice to get clarification on this. Based on descriptions within this forum, it seems like what is described in AN13037 is wrong.

Also, it would be really great to understand how the CFPA can be set based on how the CMPA is set.

Re: lpc55sxx DFLT and PIN setting clarification

ZhangJennie — Fri, 11 Nov 2022 07:22:57 GMT

HI DWightman

It's not correct. I have reported this.

Please refer table in UM11126. this is correct

The default CC_SOCU_PIN and CC_SOCU_DFLT in PFR are all zero, and not satisfied with the inverse rule, so the ROM will open all debug permission at this condition.

Bellow setting disable the access.

Hope this helps,

Jun Zhang

Re: lpc55sxx DFLT and PIN setting clarification

DWightman — Fri, 11 Nov 2022 08:44:54 GMT

Perfect, thanks for the clarification.

I do have a follow-up question regarding the CC_SOCU_PIN and CC_SOCU_NS_PIN naming convention used in the CMPA and CFPA pages respectively.

Does the "_NS" designation used in the CFPA settings imply that the PIN/DFLT fields in the CFPA are only applicable to the Non-Secure areas, and therefore the PIN/DFLT fields in the CMPA are only applicable to the Secure areas?

Since the CFPA is meant to allow restrictions for Level 2 customers, does this mean that CMPA and CFPA control different parts of the MCU?

Or, are the fields in the CC_SOCU_PIN and CC_SOCU_NS_PIN controlling the same areas, and the CFPA is only giving the option to increase the restrictions as defined in the CMPA?

Re: lpc55sxx DFLT and PIN setting clarification

DWightman — Fri, 11 Nov 2022 08:53:57 GMT

It looks like I was looking at the wrong manual, and it was for the LPC55S0x (UM11424).

And as you say the UM for the LPC55S69 (UM11126) is showing the same as the AN.

Re: lpc55sxx DFLT and PIN setting clarification

ZhangJennie — Fri, 11 Nov 2022 09:14:42 GMT

yes, please refer UM11126. This is correct.

For other manual problem, I have reported it.