Computer-System Operation ·Bootstrap program Shared memory between CPU and I/O cards Time slicing for multi-process operation Interrupt handling clock,HW,SW Implementation of system calls
- Computer-System Operation • Bootstrap program • Shared memory between CPU and I/O cards • Time slicing for multi-process operation • Interrupt handling - clock, HW, SW • Implementation of system calls
CPU user process executing 1/O interrupt processing 1/0 idle device transferring 1/O transfer 1/O transfer request done request done
Storage Structure ·Main memory(RAM) Programs must be loaded into RAM to run. Instructions and data fetched from RAM into registers. ·RAM is volatile "Medium"size and speed Other electronic volatile )memory is faster,smaller,and more expensive per bit: ·Registers ·CPU Cache Non-volatile memory("permanent"storage )is slower,larger,and less expensive per bit: ·Electronic disks ·Magnetic disks ·Optical disks ·Magnetic Tapes
- Storage Structure • Main memory ( RAM ) • Programs must be loaded into RAM to run. • Instructions and data fetched from RAM into registers. • RAM is volatile • "Medium" size and speed • Other electronic ( volatile ) memory is faster, smaller, and more expensive per bit: • Registers • CPU Cache • Non-volatile memory ( "permanent" storage ) is slower, larger, and less expensive per bit: • Electronic disks • Magnetic disks • Optical disks • Magnetic Tapes
Increasing speed registers and cost per bit cache main memory Increasing solid-state disk size magnetic disk optical disk magnetic tapes
1/O Structure 。Typical operation involves 1/O requests, -instruction execution- cycle direct memory access cache instructions thread of execution data movement. and DMA),and interrupt data handling CPU(N) DMA request interrupt memory device (M)
- I/O Structure • Typical operation involves I/O requests, direct memory access ( DMA ), and interrupt handling