BENTLY 3500/64M動(dòng)態(tài)壓力監(jiān)測器
標(biāo)準(zhǔn)PC/AT體系結(jié)構(gòu)定義了從0到4GB的內(nèi)存地址空間和從0到64KB的獨(dú)立I/O地址空間。ISA設(shè)備VMIVME-7740上的ISA設(shè)備在啟動(dòng)時(shí)由BIOS配置，并遵循標(biāo)準(zhǔn)PC/at架構(gòu)。它們被映射在標(biāo)準(zhǔn)地址內(nèi)的I/O地址空間中，它們的中斷被映射到標(biāo)準(zhǔn)中斷控制寄存器。然而，除了實(shí)時(shí)時(shí)鐘、鍵盤和可編程計(jì)時(shí)器之外，所有ISA設(shè)備都可以重新定位到標(biāo)準(zhǔn)1K字節(jié)I/O地址空間內(nèi)的任何位置。表E-1定義了可用于ISA設(shè)備重新配置的地址范圍。如前所述，在標(biāo)準(zhǔn)PC/AT系統(tǒng)中，所有I/O設(shè)備都映射在I/O地址空間中。然而，在VMIVME-7740上，動(dòng)態(tài)隨機(jī)存取存儲(chǔ)器（DRAM）、NVRAM和看門狗定時(shí)器在存儲(chǔ)器地址空間中尋址。BIOS將DRAM置于地址0，并擴(kuò)展到板載DRAM的物理極限。
The standard PC/AT architecture defines Memory address space from zero to 4 Gbyte and the separate I/O address space from zero to 64 Kbyte. ISA Devices The ISA devices on the VMIVME-7740 are configured by the BIOS at boot-up and adhere to the standard PC/AT architecture. They are mapped in I/O address space within standard addresses and their interrupts are mapped to standard interrupt control registers. However, all of the ISA devices with the exception of the real-time clock, keyboard, and programmable timer are relocatable to almost anywhere within the standard 1 Kbyte of I/O address space. Table E-1 defines the spectrum of addresses available for reconfiguration of ISA devices. As previously stated, in the standard PC/AT system, all I/O devices are mapped in I/O address space. On the VMIVME-7740, however, the Dynamic Random Access Memory (DRAM), NVRAM, and Watchdog Timer are addressed in Memory address space. The BIOS places DRAM at address zero and extends to the physical limit of the on-board DRAM.
