How to get BD address from OTP ROM

Hi Nigel,

The BD Address in placed in specific address (0x07F8EA58) in the OPT header. Please try to read the OPT Header with the OTP tool from the SmartSnippets toolbox. In order to read the BD Address from the OTP Header you should follow the procedure below:

1. Add the LLD (low level drivers) of the OTP controller

#include "hw_otpc.h"

2. Add the function which reads from the OTP memory, named read_bd_address_from_otp(). The source code is below:

static bool read_bd_address_from_otp(uint32_t otp_cell_offset, uint8_t *bd_address, uint32_t *phy_otp_address) { uint32_t r_buf[2]; uint32_t num_words = 3; uint32_t *physical_otp_address; static uint8_t bd_address_otp_final[8]; bool is_correct = 0; physical_otp_address = hw_otpc_cell_to_mem(otp_cell_offset); phy_otp_address = physical_otp_address; hw_otpc_init(); is_correct = hw_otpc_fifo_read( (uint32_t *) r_buf, otp_cell_offset ,HW_OTPC_WORD_LOW, num_words, false ); hw_otpc_disable(); bd_address_otp_final[0] = (r_buf[0] >> 0 ); bd_address_otp_final[1] = (r_buf[0] >> 8 ); bd_address_otp_final[2] = (r_buf[0] >> 16 ); bd_address_otp_final[3] = (r_buf[0] >> 24 ); bd_address_otp_final[4] = (r_buf[1] >> 0 ); bd_address_otp_final[5] = (r_buf[1] >> 8 ); bd_address_otp_final[6] = (r_buf[1] >> 16 ); bd_address_otp_final[7] = (r_buf[1] >> 24 ); memcpy(bd_address, bd_address_otp_final, 8); return is_correct; }

3. Retrieve the BD address from the OTP memory

uint32_t * physical_otp_memory_cell;uint32_t cell_offset = 0x1D4B; static uint8_t bd_address_final[8]; bool read_success; /* Retrieve the BD address from the OTP memory */ read_success = read_bd_address_from_otp(cell_offset, bd_address_final, physical_otp_memory_cell); OS_ASSERT(read_success); static own_address_t user_bd_address = { .addr_type = PRIVATE_STATIC_ADDRESS, }; memcpy(user_bd_address.addr, bd_address_final, 6); // Set BD address to the preffered value. This function sets the BD address in inverse order. ble_gap_address_set(&user_bd_address, 0x00FF);

Thanks, PM_Dialog

Hi nigelyang,

param [in] otp_cell_offset :The offset of the OTP cell. The formula to calculate the physical memory address is (0x7F80000 + (otp_cell_offset << 3)). E.g. the offset 0x1D4B corresponds to 0x7F8EA58 physical address (location of the BD address)

param [in] bd_address : The cell's contents in chunks of 1 byte

param [in] phy_otp_address : The physical address of the OTP memory cell (for verification purposes)

param [out] : True if the read request has been successfully performed, false otherwise

As I mentioned in my precious answer, the BD Address in placed in specific address (0x07F8EA58) in the OPT header. Did you read the OPT Header with the OTP tool from the SmartSnippets toolbox. Is the BD Address located into 0x07F8EA58? Otherwise, in which OTP address is located?

Thanks, PM_Dialog

Hi nigelyang,

Yes, you should read the BD Address with the same way. If you change the clock to PLL are you able to access the OPT Header from the toolbox and read the contains? If you found the previous answers useful please mark one of them as “accepted”.

Thanks, PM_Dialog