locking / unlocking SWD debug on LPC550x

mmvm — Mon, 02 May 2022 11:36:19 GMT

I found some conflicting info on how to enable/disable ISP and SWD. After some trial and error, the below appears to lock a part, but unlocking after results in a bricked device (LPC5502);

static status_t set_locked_state(cmpa_context *ctx, cmpa_cfg_info_t *buffer, bool locked) { // UM11424 pg. 136, table 184. ISP download mode based on DEFAULT_ISP_MODE bits (6:4, word 0 in CMPA) const uint32_t kISPbits = 0x70; // Do not follow UM11424 pg. 965, table 1000 - 1003. Debug access restriction levels // See AN13037 3.2.3, PIN should be 1, DFLT 0 to "debug access always disabled (pinned)" // Also see https://community.nxp.com/t5/LPC-Microcontrollers/CC-SOCU-DLFT-in-CMPA/m-p/1043919 const uint32_t kDBGbitsPin = 0xFF2000DF; const uint32_t kDBGbitsDisable = 0xFFFF0000; const uint32_t kDBGbitsEnable = 0x0000FFFF; status_t ret = FFR_GetCustomerData(&ctx->flash_instance, (uint8_t*)buffer, 0, CMPA_PAGE_SIZE); if(ret != kStatus_Success) { return ret; } // Always pin (no debug auth) buffer->dcfgPin = kDBGbitsPin; if(locked) { buffer->bootCfg |= kISPbits; buffer->dcfgDflt = kDBGbitsDisable; } else { buffer->bootCfg &= ~kISPbits; buffer->dcfgDflt = kDBGbitsEnable; } // Don't seal return FFR_CustFactoryPageWrite(&ctx->flash_instance, (uint8_t*)buffer, false); }

What values should I be using instead?

Re: locking / unlocking SWD debug on LPC550x

Alice_Yang — Thu, 12 May 2022 07:45:02 GMT

Hello,

Could you please tell me where the function come from? SDK driver?

Alice

Re: locking / unlocking SWD debug on LPC550x

mmvm — Mon, 23 May 2022 07:03:18 GMT

Hi Alice,

Apologies, I was unavailable for a bit. What function do you mean? The snippet is my code, FFR_GetCustomerData is in fsl_iap_ffr.h.

Thanks

Re: locking / unlocking SWD debug on LPC550x

Alice_Yang — Mon, 23 May 2022 09:59:59 GMT

Hello ,

About disable ISP and SWD, you can refer to attachment, this is from SE team.

About unlock, it seems need erase CMPA if can enter ISP mode.

Alice

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locking / unlocking SWD debug on LPC550x

Re: locking / unlocking SWD debug on LPC550x

Re: locking / unlocking SWD debug on LPC550x

Re: locking / unlocking SWD debug on LPC550x