Asynchronous arbiter state machine for arbitrating between operating devices requesting access to a shared resource

An arbitration system comprising:

• a resource;
• a plurality of operating means connected to said resource, each of said operating means having an output for providing a respective one of a plurality of first resource request signals to request and maintain access to said resource and having an input for receiving a respective one of a plurality of grant signals, each of said operating means accessing said resource in response to receiving the respective grant signal for said each operating means;
• latch means having a plurality of signal inputs, a corresponding plurality of signal outputs, and a control input, each of said signal inputs receiving a respective one of said first resource request signals, said control input receiving a control signal, and each of said signal outputs providing a respective one of a plurality of second resource request signals;
• said latch means for providing said first resource request signals received by said signal inputs to said signal outputs as said second resource request signals and for latching said second resource request signals in response to said control signal;
• and
• an asynchronous state machine having a plurality of inputs each receiving a respective one of said first and second resource request signals, a plurality of outputs for providing said grant signals to said plurality of said operating means, and a control output providing said control signal to said latch means, said state machine further comprising:
• first means for providing said control signal to receive said second resource request signals from said latch means,
• second means for providing said control signal in response to receiving at least one of said first and second resource request signals to latch said second resource request signals in said latch means,
• third means for arbitrating among said second resource request signals received from said latch means to select one of said operating means,
• fourth means for providing the respective one of said grant signals for said selected operating means, and
• fifth means for providing said control signal to enable said latch means to receive said first resource request signals and to provide said second resource request signals when the respective one of said first resource request signals for said selected operating means ceases to request said resource.