Abstract: A microcontroller comprising a first memory 2 used by a CPU1 to perform arithmetic operations; a second memory 3 for a multitask process for storing data transferred from an external device 30 during the arithmetic process of CPU1; bus switches 4 and 5 for switching over the connection of data buses of CPU1 and the external device 30; and an address supply portion 7, which is connected to the address bus of the external device 30 while the second memory 3 is connected to the data bus of the external device 30, and which generates address signals by which to store data from the external device, wherein this microcontroller can perform a multitask process without adopting an expensive device such as a dual port RAM.

Abstract: A mobile human machine interface for a monitoring operation of a spatially distributed control system in a factory or the like provides a location signal to a central processor holding the control program and relevant I/O data. Based on that location signal, the mobile HMI receives data relevant to the machines near its location. As the user moves through the factory, its location signal changes and the data and program which it executes changes accordingly. The user may identify him or herself to the mobile HMI providing for a second degree of discrimination in the type of data provided to the mobile HMI.