微机原理课件ch01英文.pptVIP

高级话题 8位数??16位数/32位数 无符号数 有符号数 十进制数的表示——BCD码 用4位二进制数表示一位十进制数。有两种表示法：压缩BCD码和非压缩BCD码。 压缩BCD码的每一位用4位二进制表示，0000~1001表示0~9，一个字节表示两位十进制数。 非压缩BCD码用一个字节表示一位十进制数，高4位总是0000，低4位的0000~1001表示0~9。 * 第*页 Architecture The memory and IO System * 第*页 Microprocessor Memory I/O System BUS BUS Dynamic RAM (DRAM) Static RAM (SRAM) Cache Read only (ROM) Flash memory EEPROM SDRAM RAMBUS DDR RAM 8086 8088 80186 80286 80386 80486 Pentium Pentium Pro Pentium II Pentium III Pentium 4 Printer Serial communication Floppy disk drive Hard disk drive Mouse CD-ROM drive Plotter Keyboard Monitor Tape backup Scanner DVD The memory map of the PC * 第*页 Extended Memory TPA 640K bytes System Area 384K bytes 15M bytes in the 80286 or 80386SX 31M bytes in the 80386SL/SLC 63M bytes in the 80386EX 4095M bytes in the 80386DX, 80486 and Pentium 64G bytes in the Pentium Pro, Pentium II, Pentium III, Pentium4 1M bytes of real (conventional) memory BUS Architecture * 第*页 BUS Architecture Address: If I/O, a value between 0000H and FFFFH is issued. If memory, it depends on the architecture: 20-bits (8086/8088) 24-bits (80286/80386SX) 25-bits (80386SL/SLC/EX) 32-bits (80386DX/80486/Pentium) 36-bits (Pentium Pro/II/III) Data: 8-bits (8088) 16-bits (8086/80286/80386SX/SL/SLC/EX) 32-bits (80386DX/80486/Pentium) 64-bits (Pentium/Pro/II/III) Control: Most systems have at least 4 control bus connections (active low). MRDC (Memory ReaD Control), MWRC, IORC (I/O Read Control), IOWC. * 第*页 Bus Standards ISA (Industry Standard Architecture): 8 MHz 8-bit (8086/8088), 16-bit (80286-Pentium) EISA: 8 MHz 32-bit (older 386 and 486 machines). PCI (Peripheral Component Interconnect): 33 MHz 32-bit or 64-bit (Pentiums) New: PCI Express and PCI-X 533 MTS VESA (Video Electronic Standards Association): Runs at processor speed. 32-bit or 64-bit (Pentiums) Only disk and video. Competes with the PCI but is not popular. USB (Universal Serial Bus): 1.5 Mbps,12 Mbps and now 480 Mbps. Serial connection to microprocessor., To reduce system co