Signal processor

A signal processing system comprising:

• a signal processor for receiving input signals and generating output signals in accordance with the content of the input signals, said signal processor including an internal bus for carrying signals among components of said signal processor;
• a memory;
• a first input-output control means for controlling the application of said input signals to said signal processor and the output of control signals generated by said signal processor;
• said signal processor further comprising a status register connected to said internal bus for determining whether said signal processor is using said internal bus;
• an operational means connected to said internal bus for executing an operation and providing knowledge data in accordance with said input signals provided by said first input-output control means;
• a second input-output control means coupled to said internal bus and to said first input-output control means through an input-output register, said second input-output control means storing knowledge data provided by said operational means in said memory;
• and,
• a switch means having a first switch portion connected between said input-output register and said first input-output control means and adapted to be switched off or on according to whether said internal bus is being used by said signal processor, said first switch portion controlling whether said various input signals from said first input-output means are applied to said input-output register of said signal processor.