| 摘要 |
<p>PROBLEM TO BE SOLVED: To improve the degree of freedom of system incorporation to a ROM designed for high speed specifications and utilizable without increasing the power consumption in a RON control circuit constituted so that a read-timing control signal of a ROM is generated in a circuit in which a system clock can be switched/selected to two modes of a low speed clock and a high speed clock. SOLUTION: In the ROM control circuit constituted so that a system clock of a microcomputer incorporating a ROM comprises two modes of a low speed clock and a high speed clock, and the circuit is driven in a state in which a word line at the time of pre-charge is always turned on, the circuit is characterized in that it is constituted so that duty of address buried and data strobe is 50% or less in an operation mode of a low speed clock.</p> |
