An operating method of an electronic device which includes a processor (210, 310) and a memory (220, 320), the method comprising: accessing, using the processor (210, 310), the memory (220, 320) without control of an external host device in a first bias mode; sending, from the processor (210, 310), information of the memory (220, 320) to the external host device when the first bias mode ends; accessing, using the processor (210, 310), the memory (220, 320) under control of the external host device in a second bias mode; and entering the first bias mode from the second bias mode; wherein the entering of the first bias mode from the second bias mode includes: receiving, at the processor (210, 310), data from the external host device; updating, using the processor (210, 310), the memory (220, 320) with the received data; the method further characterised by sending, from the processor (210, 310), the received data to the external host device; and entering the first bias mode in response to an acknowledgement message received from the external host device, wherein the acknowledgement message is sent from the external host device in response to a comparison of the data, which are sent from the external host device and received at the processor (210, 310), and the received data, which are sent from the processor (210, 310) and received at the external host device, indicating a match. accessing, using the processor (210, 310), the memory (220, 320) without control of an external host device in a first bias mode; sending, from the processor (210, 310), information of the memory (220, 320) to the external host device when the first bias mode ends; accessing, using the processor (210, 310), the memory (220, 320) under control of the external host device in a second bias mode; and entering the first bias mode from the second bias mode; wherein the entering of the first bias mode from the second bias mode includes: receiving, at the processor (210, 310), data from the external host device; updating, using the processor (210, 310), the memory (220, 320) with the received data; the method further characterised by sending, from the processor (210, 310), the received data to the external host device; and entering the first bias mode in response to an acknowledgement message received from the external host device, wherein the acknowledgement message is sent from the external host device in response to a comparison of the data, which are sent from the external host device and received at the processor (210, 310), and the received data, which are sent from the processor (210, 310) and received at the external host device, indicating a match. receiving, at the processor (210, 310), data from the external host device; updating, using the processor (210, 310), the memory (220, 320) with the received data; the method further characterised by sending, from the processor (210, 310), the received data to the external host device; and entering the first bias mode in response to an acknowledgement message received from the external host device, wherein the acknowledgement message is sent from the external host device in response to a comparison of the data, which are sent from the external host device and received at the processor (210, 310), and the received data, which are sent from the processor (210, 310) and received at the external host device, indicating a match.