The disclosure provides a server including a baseboard management controller (BMC), a programmable logic device (PLD) and a blocking unit. The BMC receives an update instruction, and according to the update instruction, generates a firmware update data. The BMC generates an update signal according to on a reception state of the update instruction. The PLD is coupled to the BMC, receives the firmware update data to update a firmware. When the firmware is updated, the PLD generates a restart signal. The blocking unit is coupled to the BMC and the PLD, receives the update signal and the restart signal, and according to the update signal, determines whether to block the restart signal.