SLUUDP1 November   2026 MC111 , MC121 , MC121-Q1

 

  1.   1
  2.   Abstract
  3.   Trademarks
  4. 1Introduction
  5. 2Test Programming Mode Entry and Exit:
  6. 3OTP Programming Mode Entry and Exit
  7. 4How to Determine which OTP Page is Available to Program
  8. 5Summary

3 OTP Programming Mode Entry and Exit

  1. To achieve reliable OTP memory programming through I2C communication, maintain the MC121-Q1 power supply pin voltage (VM) above 8V throughout the entire duration of the communication
  2. Pull the FG/RD pin low and apply a high frequency signal in the range of (416-833) kHz at any duty between (20-80) % for 16 to 50 cycles to the PWM/DC pin to enter the test programming mode. The I2C interface is active in test mode.
  3. Optional: To confirm if I2C is active, read address F1h. The value should be AAh.
  4. Communicate with the MC121-Q1, MC121, or MC111 over I2C to read and write to the USR_OTP registers to set the configuration to be programmed into the OTP page for desired motor performance and check the USR_TM test mode registers for the device status. Program all the reserved bit fields to 0h.
  5. Determine which OTP Page is available to program following the steps mentioned in Section 4. OTP Page 1 must be programmed first if OTP Page 2 is planned to be used in future.
  6. Select the OTP Page to be programmed with USR_OTP_PAGE_SEL bit in USR_OTP_CFG register.
  7. Write the OTP programming mode entry key 2h, 1h, 4h to the USR_OTP_PROG_UNLOCK bits in USR_OTP_PRG_UNLOCK register in successive write-frames to unlock OTP programming mode.
  8. Optional: Read the USR_OTP_PROG_UNLOCK bit to confirm if OTP program mode is active. The value should be 4h.
  9. To burn the OTP memory on selected page, write 1h to the USR_OTP_PROG_ALL bit in USR_OTP_CFG Register. The contents of the USR_OTP register will be programmed to the selected OTP page.
  10. Verify the OTP program burn by writing 1h to the USR_OTP_PROG_VERIFY bit in USR_OTP_CFG Register.
  11. Check the status at USR_OTP_CRC_ERR for no errors. Check the values at USR_OTP_PAGE_USED and USR_OTP_CRC is updated.
  12. To exit the OTP mode write key 2h, 1h, 4h to the USR_OTP_PROG_UNLOCK bits in USR_OTP_PRG_UNLOCK register in successive write-frames or power cycle the device.
  13. To exit I2C mode write value BBh at address F1h or power cycle the device.
  14. The configured settings are loaded from the programmed OTP page after power cycle.