Ex parte LOO et al. - Page 2




          Appeal No. 95-4714                                                          
          Application No. 08/046,476                                                  



          entry by the examiner, it has not been considered.                          
               The invention is a flushing system for a virtual cache                 
          memory in a computer workstation.  Claim 13, which is one of the            
          three independent claims on appeal (claims 17 and 23 are the                
          others), reads as follows:                                                  
                    13. In a computer workstation operating in                        
               accordance with a shared, multi-user operating system                  
               having multiple concurrently active contexts and having                
               a kernel wherein virtual addresses are assigned for                    
               each of a plurality of users, said workstation having a                
               central processor and a cache data array coupled to an                 
               address bus, said cache data array including a                         
               plurality of cache blocks each one having a cache block                
               address and an associated cache block tag, a system for                
               completing a cache block flush operation, comprising:                  
                    flush control logic means coupled to said address                 
               bus for controlling said cache block flush operation                   
               after receipt of a flush command from said central                     
               processor, said flush control logic means issuing a                    
               signal and asserting control of said address bus after                 
               receipt of said flush command, said flush control logic                
               means retaining control of said address bus until said                 
               cache block flush operation is completed;                              
                    reset means coupled to said flush control logic                   
               means for setting and resetting elements of said cache                 
               block tags;                                                            
                    a plurality of cache flush control means disposed                 
               within said kernel of said shared, multi-user operating                
               system and responsive to said signal issued by said                    
               flush control logic means, each of said flush control                  
               means comparing preselected portions of said cache                     
               block address and elements of said cache block tag for                 
               each of said plurality of cache blocks to different                    
               preselected criteria, said flush control means then                    
               flushing said cache blocks to said main memory if said                 
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