algorithm ISA microarchitecture global optimum/local optimum steering bit segmentation operate/data movement/control instructions addressing mode immediate value indirect addressing design tradeoffs memory-mapped I/O byte-addressable address space fixed length vs. variable length uniform decode little endian big endian addressability word length operate instructions data type 0-address machine 1-address machine 2-address machine 3-address machine data movement instructions load/store ISA vs non-load/store ISA predicated execution architectural state control instructions condition codes PC-relative addressing prefix compatability assembler assembly language location counter label pseudo-op virtual machine microsequncer control structure microinstruction datapath critical path design speed path state machine fetch stage decode stage clock skew SRAM DRAM nonvolatile memory capacitor DRAM refresh chip enable row address strobe column address strobe page mode (in terms of memory chips) memory controller unaligned access interleaving memory bank memory row virtual memory physical memory thrashing disk block disk access time page fault page table entry page frame resident protection bits length register hardware context program counter processor status register general purpose registers page table base register process context switch working set balance set address translation access control translation lookaside buffer hit ratio CAM (content-addressable memory) access control logic privilege levels access levels reference bit VAX virtual memory system space user space walking the page table segment descriptor segment register modified (dirty) bit valid bit cache cache consistency memory hierarchy cache line cache block temporal locality spatial locality direct mapped cache set associative cache tag index tag store associative memory fully associative cache write back copy back write through store buffer allocate on a write miss replacement policy prefetch post store LRU pseudo LRU FIFO random replacement victim/next victim index sector cache virtual cache virtually-indexed physically-tagged physical cache synonym problem back translation interrupt exception consistent state integer overflow fault trap trace bit trace trap machine check interrupt power failure vectoring interrupt/exception vector table service routine/handler maskable priority context