SLAAEU3 June   2025 MSPM0C1104

 

  1.   1
  2.   Abstract
  3.   Trademarks
  4. 1Four Wire Cooling Fans
  5. 2Cooling FAN Controller with MSPM0 Designs
    1. 2.1 Design with MSPM0C1104 and MSPM0C1106
    2. 2.2 Design with MSPM0H3215 and MSPM0H3216
  6. 3Software Introduction
    1. 3.1 Software Working Flow
    2. 3.2 Function Description
      1. 3.2.1 PWM Output
      2. 3.2.2 TACH Capture
      3. 3.2.3 ADC Sample
      4. 3.2.4 FAN Fault Detection and Overflow Maximum Value
    3. 3.3 I2C Communication Protocol
    4. 3.4 Registers Definition in the Demo
  7. 4Demo Test with Hardware
    1. 4.1 Hardware Setup
    2. 4.2 Software Setup
    3. 4.3 Running Demo Code
  8. 5Summary
  9. 6References

3.2.4 FAN Fault Detection and Overflow Maximum Value

This demo code can support fan fault detection. If the fan PWM duty cycle is not 0, but there is no TACH signal capture for configured overflow maximum value of the overflow event or zero event of the TACH capture timer, the fan is in fault status and is recorded in the 0x60 register. For this register, one bit equates to the status of one fan. The overflow maximum value also can be configured at register 0x50. The default value is 3. That means if fan 1 started but there is no TACH signal is captured in 3 × 600ms = 1.8s, fan 1 is recorded as fault. Every time the fault detection register fault is read, the event clears. TI does not recommend reading the value two times within 1.8s, or the second time read value is always 0.