Patent ID: 6018785
Filing Date: 2000-01-25
Classification: G06F

Abstract:
An apparatus comprising:a first port;a second port;a resource coupled to said first port and said second port, accessible through at least one of said first port and said second port by a plurality of processes, wherein only one of the processes can access the resource at any one time;a hardware semaphore configured to store a value indicating the availability of said resource to the plurality of processes, said hardware semaphore comprising (i) a first and a second read latch and (ii) a plurality of output latches each having a data input, an output and a latch enable input, wherein an output of the hardware semaphore is connected to the input of a respective output latch, and an output of each output latch connected to the input of a respective read latch; andan interrupt circuit, connected to said hardware semaphore and said plurality of processes, said interrupt circuit generating an interrupt in response to a change in the availability of said resource as represented by the value stored in the hardware semaphore.