Expanded functionality of processor operations within a fixed width instruction encoding

Abstract

An apparatus for executing fixed width instructions in a multiple execution unit system has a means for fetching instructions from memory, and a decoder for decoding each fetched instruction in turn. A determination is made as to whether each decoded instruction includes a portion to fetch a locally stored instruction from a local store. If it does, the locally stored instruction is fetched and locally stored portion are executed.

1 . Apparatus for executing fixed width instructions in a multiple execution unit system comprising: 
 means for fetching instructions from memory;    means for decoding each fetched instruction in turn;    means for determining whether each decoded instruction includes a portion to fetch a locally stored instruction portion from a local store means;    means for fetching the locally stored instruction portion in dependence on the determination; and    means for causing the decoded instruction and locally stored instruction portion to execute on at least one of the execution units.    
     
     
         2 . Apparatus according to  claim 1  including means for storing additional local instructions in the local storage means in response to data included in a fetched instruction.  
     
     
         3 . Apparatus according to  claim 2  in which the data included in the fetched instruction includes data defining the location in the local storage means into which the additional local instruction to be written.  
     
     
         4 . Apparatus according to  claim 1 ,  2  or  3  in which locally stored instructions comprises at least a functional portion defining the type of operation to be performed.  
     
     
         5 . A method for executing fixed width instructions in a multiple execution unit system comprising the steps of: 
 fetching instruction from memory;    decoding each fetched instruction in turn;    determining whether each decoded instruction includes a portion to fetch locally stored instruction portion;    fetching the locally stored instruction portion in dependence in the determination; and    causing the decoded instruction and locally stored instruction portions to execute on at least one of the execution units.    
     
     
         6 . A method according to  claim 5  including the step of storing additional local instruction in response to data included in a fetched instruction.  
     
     
         7 . Apparatus according to  claim 6  in which the data included in the fetched instruction includes data defining the location in a local storage means into which the additional local instruction is to be stored.  
     
     
         8 . A method according to claims  5 ,  6  or  7  in which the locally stored instruction comprises at least a functional part defining the type of operation to be performed.  
     
     
         9 . Apparatus for executing fixed width instructions in a multiple execution unit system substantially as herein described with reference to the drawings.  
     
     
         10 . A method for executing fixed width instructions in a multiple execution unit system substantially as herein described with reference to the drawings.