m Part4 Extensive Reading /Hybrid Memories As memory technology has matured in recent years, the line between RAM and roM has blurred使模糊).NoW, several types of memory combine features of both. These devices do not belong to either group and can be collectively referred to as hybrid混合的 memory devices. Hybrid memories can be read and written as desired, like RAM, but maintain their contents without electrical power, just like ROM. Two of the hybrid devices, EEPROM and flash, are descendants(后裔,后代 of roM devices. These are typically used to store code. The third hybrid, NVRAM, is a modified version of SRAM. NVRAM usually holds persistent持久的,永久的data EEPROMs are electrically-erasable-and-programmable. Internally, they are similarto EPROMS, but the erase operation is accomplished electrically, rather than by exposure to ultraviolet(yp 线的川 light. Any byte within an EEPROM may be erased and rewritten 202120P102021/2/20 P.10 Hybrid Memories As memory technology has matured in recent years, the line between RAM and ROM has blurred(使模糊). Now, several types of memory combine features of both. These devices do not belong to either group and can be collectively referred to as hybrid(混合的) memory devices. Hybrid memories can be read and written as desired, like RAM, but maintain their contents without electrical power, just like ROM. Two of the hybrid devices, EEPROM and flash, are descendants(后裔, 后代)of ROM devices. These are typically used to store code. The third hybrid, NVRAM, is a modified version of SRAM. NVRAM usually holds persistent(持久的，永久的)data. EEPROMs are electrically-erasable-and-programmable. Internally, they are similar to EPROMs, but the erase operation is accomplished electrically, rather than by exposure to ultraviolet(紫外 线的)light. Any byte within an EEPROM may be erased and rewritten & Part4 Extensive Reading