Abstract: An apparatus and method for arbitrating requests for access to a shared resource. A buffer, on command from control logic, can selectively couple or decouple two buses. The control logic uses signals from two logic devices, one of which may be a microprocessor, and one of which may be a communications interface, to determine which of the devices is granted access to the shared resource. The control logic can generate an inhibit signal to the microprocessor to stall it while the second logic device is accessing the shared resource. Handshaking is used to control access by the second device to the shared resource.