嵌入式处理器的特征 USTC General rules (with exceptions): 1.Designed for efficiency (vs.ease of programming) 2.Huge variety of processors(resulting from 1.) 3.Harvard architecture 4.Heterogeneous register sets 5.Limited instruction-level parallelism or VLIW ISA 6.Different operation modes (saturating arithmetic,fixed point) 7.Specialised microcontroller DSP instructions (bit- reversal,multiply/accumulate,bit-field addressing,modulo addressing) 8.Multiple memory banks 9.No "fat"(MMU,caches,memory protection,target buffers, complex pipeline logic,... These features have to be known to the compiler! llxx@ustc.edu.cn 9/87嵌入式处理器的特征 • General rules (with exceptions): 1. Designed for efficiency (vs. ease of programming) 2. Huge variety of processors (resulting from 1.) 3. Harvard architecture 4. Heterogeneous register sets 5. Limited instruction-level parallelism or VLIW ISA 6. Different operation modes (saturating arithmetic, fixed point) llxx@ustc.edu.cn 9/87 7. Specialised microcontroller & DSP instructions (bit￾reversal, multiply/accumulate, bit-field addressing, modulo addressing) 8. Multiple memory banks 9. No “fat” (MMU, caches, memory protection, target buffers, complex pipeline logic, ...) • These features have to be known to the compiler!