EXPLICIT STORE-TO-INSTRUCTION-SPACE INSTRUCTION FOR SELF-MODIFYING CODE AND ENSURING MEMORY COHERENCE BETWEEN INSTRUCTION CACHE AND SHARED MEMORY USING A NO-SNOOP PROTOCOL

A method and apparatus for performing a store-to-instruction-space instruction are provided. A unique opcode indicates that a data value is to be written to an instruction space in main memory. The instruction is received and executed. After the instruction space is modified to contain the data value, further processing is performed to ensure coherence between main memory and an instruction cache.