| 摘要 |
<P>PROBLEM TO BE SOLVED: To prevent degradation in operation performance of a CPU and a sound source section, in an integrated circuit connected with an external ROM in which a program and data for a sound source are stored. <P>SOLUTION: A program and a waveform ROM 3 are externally connected to a sound source LSI 1 via an external memory input and output section comprising selector 12, a gate circuit 13 and an S signal generation circuit 14. When an electronic musical instrument 1 starts operation, the S signal generation section 14 outputs a first selection information, and the first selection information is set in the selector 12, and the CPU 10 can access to the external ROM 3. The CPU 10 transfers a program body from the external ROM 3 to a RAM, and jumps to a transfer destination. The CPU 10 executes the program from the RAM of a jump destination, and second selection information is output from the S signal generation section 14, and it is set in the selector 12. After that, the sound source section 11 can access to the external ROM 3. The CPU 10 executes the program from the RAM and controls operation of an electronic musical instrument 2. <P>COPYRIGHT: (C)2010,JPO&INPIT |
