Static Random BD Address calculation issue

ID: LPCBARESDK-770

Status: Open

First reported: 6.0.14.1114

Fixed in: TBD

Description

For the DA14585/DA14586 device family, the default_app_generate_unique_static_random_addr() does not generate a static random device address as unique as one would expect. Potential address collisions might occur when the use application define the USER_CFG_ADDRESS_MODE as APP_CFG_ADDR_STATIC.

Workaround

The modification below will guarantee each unique device address is generated from a unique seed.

In the sdk/app_modules/src/app_default_hnd/app_default_handlers.c, apply:

@@ -304,13 +304,8 @@ void default_app_generate_unique_static_random_addr(struct bd_addr *addr)
         val1 = timestamp ^ position ^ adc_single;
         val2 = tester ^ package ^ adc_diff;
 #else
-        timestamp = GetWord32(OTP_TIMESTAMP_ADDR);  // Device time stamp
-        siteID = GetWord8(OTP_SITE_ID_ADDR) & 0x7;  // Get the Site ID (3-bits)
-        timestamp ^= (siteID << 30);                // Add test site to MSB
-
-        trim = siteID >> 2;                         // MSb of Site ID
-        trim |= (GetWord8(OTP_BANDGAP_ADDR) & 0x3F) << 1;   // Bandgap trim (6-bits)
-        trim |= (GetWord8(OTP_LNA_ADDR) & 0x7F) << 7;       // LNA trim (7-bits)
+        timestamp = GetWord32(OTP_TIMESTAMP_ADDR);  // Device time stamp (32-bits)^M
+        siteID = GetWord32(OTP_SITE_ID_ADDR);  // Get the Site ID (32-bits)^M

         val1 = timestamp;
         val2 = trim;

This modification only applies when the address mode in the user_config.h is configured as:

#define USER_CFG_ADDRESS_MODE       APP_CFG_ADDR_STATIC