Abstract: An arrangement of a master device and a slave device, includes one or more physical memory means and a plurality of logical memory means, wherein one or more of the logical memory means are permanently accessible by the master device and one or more further logical memory means may be accessed by the master device in response to a pre-determined access code being received at a pre-determined memory location.

Abstract: Existing packages for photodiodes employ a silicone sealant to prevent moisture ingress and an adhesive to encapsulate the silicone covered photodiode. Differing coefficients of thermal expansion of the silicone and the adhesive can result in the disadvantageous formation of vacuum voids. The present invention overcomes this disadvantage by providing a package in which a silicon micro-bench supports a photodiode, the photodiode being substantially covered with silicone and not further encapsulated with an adhesive.