Patent ID: 8793517

Claim:
A motherboard comprising: a voltage-state display system comprising: a first transistor comprising a control terminal, a first terminal grounded, and a second terminal; a second transistor comprising a control terminal, a first terminal grounded, and a second terminal; a first light emitting diode (LED) connected to the second terminal of the first transistor; a second LED connected to the second terminal of the second transistor; and a power management chip comprising: a first phase output terminal connected to the control terminal of the first transistor to output a first pulse width modulation (PWM) signal; and a second phase output terminal connected to the control terminal of the second transistor to output a second PWM signal; a drive connected to the first and second phase output terminals to receive the first and second PWM signals, and output a voltage according to the received first and second PWM signals; and a central processing unit (CPU) connected to the drive to receive the output voltage from the drive, and connected to the power management chip to output a control instruction to the power management chip to denote a voltage mode provided to the CPU, thereby controlling the power management chip to adjust the first and second PWM signals; wherein when the power management chip is in a PS 0 state, the first phase output terminal continuously outputs the first PWM signal to the control terminal of the first transistor, and the second phase output terminal continuously outputs the second PWM signal to the control terminal of the second transistor, the first and second LEDs is lit to denote the voltage mode of the CPU is the PS 0 mode; when the power management chip is in a PS 1 state, the first phase output terminal continuously outputs the first PWM signal to the control terminal of the first transistor, while the second phase output terminal does not output the second PWM signal, the first LED is lit, and the second LED is not lit, to denote the voltage mode of the CPU is the PS 1 mode; when the power management chip is in a PS 2 state, the first phase output terminal discontinuously outputs the first PWM signal to the control terminal of the first transistor, while the second phase output terminal does not output the second PWM signal, the first LED flickers, and the second LED is not lit, to denote the voltage mode of the CPU is the PS 2 mode.