input signal ext_in but these two timers are controlled by a single input port having an interrupt function that is there is no need to use a plurality of input ports for the measurement of a single signal moreover as compared with the prior art described earlier with reference to fig2 there is a lower risk of a measurement result stored in the registers being destroyed by being overwritten with the next measurement result because of shortage of processing time as far as similar microprocessor processing is concerned as will be clear from these two points it is possible to build peripheral circuits having intelligent functions without minimum redundancy comparable to the peripheral circuits of a microcomputer designed for a special purpose 0124 fig1 shows a flow chart of another example of the program for building peripheral circuits having predetermined functions first the registers reg 0 to reg 29 are set as follows reg 0 1 reg 1 1 reg 2 0 reg 3 0 reg 4 0 reg 5 1 reg 6 0 reg 7 0 reg 8 1 reg 9 0 reg 10 0 reg 11 0 reg 12 0 reg 13 0 reg 14 1 reg 15 0 reg 16 0 reg 17 1 reg 18 0 reg 19 0 reg 20 0 reg 21 1 reg 22 0 reg 23 0 reg 24 0 reg 25 0 reg 26 1 reg 27 0 reg 28 0 and reg 29 1 s 401 next the address to which to make access is set in the selectors 401 to 410 of the connecting circuit 4 specifically write.