Patent ID: 8321707

Claim:
A main computer for a vehicle, comprising: a central processing unit, for controlling operations of the main computer; and a programmable logic device, coupled to the central processing unit, the programmable logic device having a built-in power state machine for managing power statuses of the main computer, wherein the power state machine comprises a turn-off status, an operating status, and a battery fault and process status located between the turn-off status and the operating status; and a battery device; wherein when the supply voltage of the battery device is smaller than a predetermined voltage, the power state machine transits from the operating status into the battery fault and process status; and wherein when a time during the supply voltage of the battery device is smaller than the predetermined voltage is smaller than a first predetermined time, the power state machine transits from the battery fault and process status into the operating status; wherein the power state machine further comprises a power off status for turning off a power of the central processing unit and the programmable logic device; and when the time during the supply voltage of the battery device is smaller than the predetermined voltage is greater than the first predetermined time, the power state machine transits from the battery fault and process status into the power off status; wherein the power state machine further comprises a programmable logic device enabling status for providing power to the programmable logic device; and when the supply voltage of the battery device reaches the predetermined voltage, the power state machine transits from the power off status into the programmable logic device enabling status; wherein the power state machine further comprises a power pre-enabling status for preparing to provide power to the central processing unit; and when a time during the supply voltage of the battery device reaches the predetermined voltage is greater than a second predetermined time, the power state machine transits from the programmable logic device enabling status into the power pre-enabling status; wherein when the programmable logic device receives a main computer power on signal, the power state machine transits from the power pre-enabling status into the operating status.