| 摘要 |
<p>PROBLEM TO BE SOLVED: To substantially reduce power consumption by disposing a circuit for dynamically shifting a circuit block without the need of an operation among the plural circuit blocks to a low power consumption state. SOLUTION: A clock stoppage control circuit 42 inside a memory management unit 4 monitors the high-order three bits of address signals on a logical address bus 8a and judges which one of a cache area and a non-cache area a central processing unit 1 accesses and whether or not a so-called fixed physical space accessible only by a physical address is accessed. Then, control signals are sent to a clock supply/interruption circuit 19 and the supply of clock signals to a cache controller 7 is stopped at the time of accessing the non-cache area. Also, at the time of accessing the fixed physical space, the supply of the clock signals to the control part 41 of an address conversion circuit for converting a logical address to the physical address is stopped.</p> |
