| 摘要 |
PROBLEM TO BE SOLVED: To reduce the load on a bus transfer required for a processor to acquire a semaphore bit concerning exclusive control, for which the semaphore bit is used, in a multiprocessor system for accessing shared resources. SOLUTION: A semaphore register 1 has plural semaphore bits and a processor part 21 reads the plural semaphore bits from the semaphore register 1, transits an open semaphore bit, which corresponds to a shared device not to be accessed, among semaphore bits transited to occupancy into non-occupancy, accesses the shared device corresponding to the occupied acquired semaphore bit and transits that acquired semaphore bit into non-occupancy later.
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