Patent ID: 6973025
Filing Date: 2005-12-06
Classification: G06F

Abstract:
1. A device for selecting a normal circuit in a communication system comprising: at least one pair of general function circuit modules; one pair of control function circuit modules, each of the control function circuit modules including at least one first selecting circuit that selects one of the two general function circuit modules in each of said at least one pair that is in normal operation and provides a respective function failure signal when the control function circuit modules have function failure; one pair of power supply modules that supply power to the modules and provide a respective power fail signal when a power failure occurs; a separate processor that controls the modules; and a second selecting circuit that switches states of the two control function circuit modules responsive to the control of the processor and the failure signals, wherein the second selecting circuit switches the control function circuit module of the pair in an active state to a standby state after switching the control function circuit module of the pair in the standby state to the active state, wherein the processor enables read/write states of the control function circuit module in the active state, and wherein the processor enables only a read state of the control function circuit module in the standby state to prevent an output state of the control function circuit module in the active state from being changed by the output state of the control function circuit module in the standby state.