BENTLY 3500/64M动态压力监测器
标准PC/AT体系结构定义了从0到4GB的内存地址空间和从0到64KB的独立I/O地址空间。ISA设备VMIVME-7740上的ISA设备在启动时由BIOS配置，并遵循标准PC/at架构。它们被映射在标准地址内的I/O地址空间中，它们的中断被映射到标准中断控制寄存器。然而，除了实时时钟、键盘和可编程计时器之外，所有ISA设备都可以重新定位到标准1K字节I/O地址空间内的任何位置。表E-1定义了可用于ISA设备重新配置的地址范围。如前所述，在标准PC/AT系统中，所有I/O设备都映射在I/O地址空间中。然而，在VMIVME-7740上，动态随机存取存储器（DRAM）、NVRAM和看门狗定时器在存储器地址空间中寻址。BIOS将DRAM置于地址0，并扩展到板载DRAM的物理极限。
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.
