EMERSON 5X00321G01 DCS卡
每種設(shè)備類型的訪問定時都是可編程的，取決于初始化期間VPD中的設(shè)備定時數(shù)據(jù)。MVME7100上提供了硬件閃存組寫保護(hù)開關(guān)，以啟用NOR閃存的寫保護(hù)。無論NOR閃存控制/狀態(tài)寄存器中的軟件閃存寫保護(hù)位的狀態(tài)如何，當(dāng)該開關(guān)處于ON時，寫保護(hù)都會啟用。當(dāng)該開關(guān)為OFF時，寫防護(hù)由軟件閃存寫防護(hù)位的狀態(tài)控制，并且只能通過清除NOR閃存控制/狀態(tài)寄存器的該位來禁用。請注意，F(xiàn)_WE_HW位反映交換機(jī)的狀態(tài)，并且僅是軟件可讀的，而F_WP_SW位同時支持讀和寫操作。MVME7100提供了一個雙引導(dǎo)選項(xiàng)，用于從引導(dǎo)閃存庫中的兩個單獨(dú)的引導(dǎo)映像（稱為引導(dǎo)塊a和引導(dǎo)塊B）中的一個引導(dǎo)。引導(dǎo)塊a、B的大小各為1MB，位于引導(dǎo)閃存空間的頂部（最高地址）2MB。
Access timing for each device type is programmable and depends on the device timing data found in the VPD during initialization.A hardware flash bank write protect switch is provided on the MVME7100 to enable write protection of the NOR Flash. Regardless of the state of the software flash write protect bit in the NOR Flash Control/Status register, write protection is enabled when this switch is ON. When this switch is OFF, write protection is controlled by the state of the software flash write protect bits and can only be disabled by clearing this bit in the NOR Flash Control/Status register. Note that the F_WE_HW bit reflects the state of the switch and is only software readable whereas the F_WP_SW bit supports both read and write operations. The MVME7100 provides a dual boot option for booting from one of two separate boot images in the boot flash bank which are referred to as boot block A and boot block B. Boot blocks A and B are each 1MB in size and are located at the top (highest address) 2MB of the boot flash memory space.
