Secure

Trim Lock Register offset 0x8.

Trim Lock Register offset 0x8Controls write access to oscillator trim and calibration registers. Provides security mechanism to prevent accidental modification of critical frequency calibration values that affect system timing.

微調鎖定暫存器，控制振盪器校準值的寫入保護

Lock Mechanism:

• Write specific unlock sequence to enable trim register access
• Automatically locks after trim modifications to prevent accidents
• Protects factory calibration values from corruption
• May require multiple unlock steps for enhanced security

註

Security Features:

• Prevents accidental frequency changes during normal operation
• Protects against software bugs that might corrupt calibration
• May be permanently locked in production devices
• Unlock sequence typically requires specific write pattern

警告

Critical Safety:

• Only unlock when intentionally modifying trim values
• Always re-lock after trim modifications complete
• Verify trim changes don't violate timing requirements

• Document any trim modifications for maintenance records

  Trim Operation:

  // Unlock trim registers for calibration
  scg->trim_lock = TRIM_UNLOCK_KEY_1;
  scg->trim_lock = TRIM_UNLOCK_KEY_2;
   
  // Perform calibration adjustments
  scg->firctrim = new_trim_value;
   
  // Re-lock trim registers
  scg->trim_lock = TRIM_LOCK_VALUE;