1. A method of securing a data mapping function in an electronic device that employs a normal data mapping arrangement to carry out the data mapping function during a normal operating mode, wherein the normal data mapping arrangement comprises a first data mapping module and a second data mapping module in a first combined arrangement that is configured to carry out the data mapping function during the normal operating mode, the method comprising: receiving a configuration signal to initiate scan testing; and in response to the configuration signal, reconfiguring the normal data mapping arrangement into a scanning data mapping arrangement for a scanning mode by arranging the first data mapping module and the second data mapping module in a second combined arrangement that is configured to carry out a data masking function during the scanning mode, the scanning data mapping arrangement being configured to scan protect the data mapping function while allowing scan testing of the electronic device.