Abstract: A low power keyword based speech recognition hardware architecture for hands free wake up of devices is provided. This system can be used in always ON domain for detection of voice activity, due to its low power operational ability. The system goes into deep low power state by deactivating all the non-required processes, if no activity is detected for a pre-specified time. Upon detection of the valid voice activity the system searches for the detection of the spoken keyword, if the valid keyword is detected, all the application processes are activated and system goes into full functional mode and if the voice activity doesn't contain the valid keyword present in the database then the system goes back into the deep low power state.