topic Re: CC_SOCU_DLFT in CMPA in LPC Microcontrollers

CC_SOCU_DLFT in CMPA

kamii — Tue, 30 Jun 2020 06:07:37 GMT

Hello,

We'd like LPC55S69 to enter "OEM Closed" lifecycle state and close all debug ports permanently.

For this transition, which CMPA configuration is correct?

[Configuration 1]

CMPA.CC_SOCU_PIN = 0xFC00.03FF

CMPA.CC_SOCU_DFLT = 0xFC00.03FF (all SOCU_DFLT[n] bit to 1)

[Configuration 2]

CMPA.CC_SOCU_PIN = 0xFC00.03FF

CMPA.CC_SOCU_DFLT = 0xFFFF.0000 (all SOCU_DFLT[n] bit to 0)

I'd like to confirm the SOCU_DFLT[n] bit polarity.

I'm looking the Table 1062 "Access restriction levels" in UM11126 Rev.2.0, and that shows that "SOCU_PIN[n] = 1 and SOCU_DFLT[n] = 1" mean Restriction Level 3 (Access to the sub-domain is permanently disabled), so I think the above Configuration 1 is correct for disabling debug ports.

Best Regards,

Re: CC_SOCU_DLFT in CMPA

nxf58474 — Wed, 01 Jul 2020 17:36:10 GMT

Hi,

Hope you are doing well. The correct configuration would be the second one. There is a documentation issue in the version of the User Manual.

CC_SoCU_DFLT setting defines the default access rights for corresponding debug domains.

– If bit is set, access is allowed. Otherwise access is denied.

CC_SoCU_PIN setting defines if debug authentication process can modify the access rights defined by CC_SoCU_DFLT:

– If bit is clear, access rights to corresponding debug domain are determined via debug authentication process.

– If bit is set, access right as defined CC_SoCU_DFLT cannot be altered.

– SOCU_PIN[n] = 1, SoCU_DFLT[n] = 0: This offers the highest level of restriction.

– SOCU_PIN[n] = 0, SOCU_DFLT[n] = 0/1: This setting allows debug authentication process to define access rights.

– SOCU_PIN[n] = 1, SOCU_DFLT[n] =1: This setting is lowest security level.

Hope this helps.

Best Regards,

Ricardo

Re: CC_SOCU_DLFT in CMPA

kamii — Thu, 02 Jul 2020 00:16:50 GMT

Hi,

Thank you for your answer! I understand that's a documentation issue. I was confused about inconsistency between the documentation and my testing result.

I think that table is important for security level description, so could you please consider to modify the UM?

Thank you.

Re: CC_SOCU_DLFT in CMPA

nxf58474 — Thu, 02 Jul 2020 14:33:14 GMT

Hi,

Yes, the new upcoming release of the User Manual should have this modification.

Thank you for your observation.

Best Regards,

Ricardo

Re: CC_SOCU_DLFT in CMPA

kamii — Fri, 31 Jul 2020 04:55:21 GMT

Hi,

I've found the latest User Manual Rev.2.1, but that documentation isn't modified. When will you apply the modification?

Best Regards,