| 摘要 |
PURPOSE:To rewrite a microprogram to form a sequence detecting circuit, by setting the state of a signal to be detected to an expected value register and making it possible to select and execute different processing procedures for the same change of the noticed signal. CONSTITUTION:Respective bits of an expected value register 1 are allowed to correspond to signals A-H of a signal group 2 and are set to 0 or 1 in accodance with the state of a signal to be detected of each bit. NOT of exclusive OR between each bit of the register 1 and a corresponding signal of the signal group 2 is operated in an XNOR network 3. AND between the bit output from a mask register 4 corresponding to the output of the network 3 and a corresponding bit outputted from the network 3 is operated in an AND network 5. Eight outputs from the network 5 are selected preferentially and are encoded by a priority encoder 6 and are applied to a microprogram memory through an address determining circuit 8 by an address from an internal state memory 7, and the program is rewritten and is executed. |
