| 摘要 |
PURPOSE:To make a register execute different operations, by applying an access signal to at least one register, and making it decide whether access is available or not in accordance with 2 states, in an access system of the register of a microprogram control information processing device. CONSTITUTION:When a micro-instruction is set to a micro-instruction register 107 from a microprogram memory 109, contents of a part 108 of its register are led to an access control device 110, and an access request signal MREG and RREQ are generated. In this case, an interruption factor register 202 does not permit write from software and write is not available in case when the signal NREQ is outputted, but the signal MREQ is applied to a main memory 204. Also, a register 203 permits read-out and write-in from software, therefore, both the signal MERQ and RREQ are accessed. |
