Ex parte LOO et al. - Page 6




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



          has been checked (Spec. at 29, lines 20-22).                                
               During a flush operation, all thirty-two cache blocks in the           
          cache data array are addressed in sequence using the virtual                
          address bits A(8:4) generated by 5-bit incrementer 50 (Spec. at             
          29, lines 10-15).  As is apparent from Figure 11, an addressed              
          cache block is flushed (i.e., a Flush Match signal is generated             
          by OR gate 58 of Fig. 11) only if the Context Flush, Page Flush,            
          or Segment Flush signal stored in one of flip-flops 49 is applied           
          to one input of an AND gate 55 at the same time that a Context              
          Match, Page Match, or Segment Match signal is applied to the                
          other input of that AND gate.  These Match signals are produced             
          by the circuitry shown in Figure 12 (Spec. at 28, lines 18-20),             
          which compares the virtual address A(27:4) of the addressed cache           
          block (including the cache block address and the associated                 
          address information in the cache tag array) with the virtual                
          addresses to be flushed, compares the context identification                
          bits CX(2:0) of the addressed cache block with the context                  
          identification bits of the virtual addresses to be flushed, and             
          examines the Valid (V), Modified (M), and Protection (P) bits               
          stored in the cache tag array for the addressed block (Spec. at             
          15-17).                                                                     
               The foregoing elements clearly perform the functions                   
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