Bus band control device and bus band control method

A bus band control device which, in a system in which a CPU core set which executes a plurality of programs, and a plurality of resources, are connected via a bus, controls a band of the bus used by the programs, the bus band control device comprising:

• a resource division mechanism which is connected to the bus and determines ranges of the resources that are accessible by the respective programs;
• a hardware timer which performs an interrupt to the CPU core set at a predetermined timing;
• a shared memory which is one of the resources and has storage areas respectively allocated to the plurality of programs by the resource division mechanism;
• and
• a bus band restriction program which is executed by the CPU core set and which, when the interrupt is performed, causes execution of occupation processing for the CPU core set, and when the occupation processing is finished, brings processing of the CPU core set back into a state before the interrupt, wherein
• the storage areas include a vector table indicating processing to be executed when the interrupt is performed, and a storage area that the bus band restriction program uses, and
• the resource division mechanism permits only the bus band restriction program to access the hardware timer, the vector table, and the area that the bus band restriction program uses.

A bus band control method for, in a system in which a CPU core set which executes a plurality of programs, and a plurality of resources, are connected via a bus, controlling a band of the bus used by the programs, the bus band control method comprising the steps of:

• performing an interrupt to the CPU core set by a hardware timer at a predetermined timing;
• executing occupation processing for the CPU core set when the interrupt is performed;
• and
• bringing processing of the CPU core set back into a state before the interrupt when the occupation processing is finished, wherein
• storage areas of a shared memory which is one of the resources include a vector table indicating processing to be executed when the interrupt is performed, and a storage area that a bus band restriction program for executing the occupation processing uses, and
• only the bus band restriction program is permitted to access the hardware timer, the vector table, and the storage area that the bus band restriction program uses.