论文部分内容阅读
非易失存储器有很多类型,容量也各不相同.这种存储器的涵盖范围很广,从价格低廉但灵活性不强的只读存储器(ROM)一直到价格昂贵但十分灵活的电可擦可编程存储器(EEPROM).各类非易失存储器之间的主要差别是编程和擦除的灵活性.ROM具有结构最紧凑的芯片存储器阵列布局,因而价格最低,但是存储器内容在生产阶段是固定的.比较灵活的是一次可编程 EPROM(OTP ROM).这种存储器在生产后可以电编程一次,这就使用户在设备组装时有能力把最新版本的内容装入存储器.EPROM具有类似的性能,但是又增加了另一层灵活性,同为它还可以暴露在强紫外(UV)光下擦除后重新编程.但是,擦除时间需要20分钟,而且重新编程是用一个专用编程器完成的.
There are many types of nonvolatile memory with different capacities. This memory covers a wide range of products, from inexpensive but less flexible read-only memories (ROMs) to expensive but highly flexible electrically erasable Programming Memory (EEPROM). The main difference between the various non-volatile memories is the flexibility of programming and erasing. The ROM has the most compact layout of the chip memory array and hence the lowest price, but the memory content is fixed during the production phase More flexible is the One Time Programmable EPROM (OTP ROM), a type of memory that can be electronically programmed once it is manufactured, giving users the ability to load the latest version of content into their memory when the device is assembled.EPROM has similar performance, But adds yet another level of flexibility, as it can also be reprogrammed after being erased by exposure to intense ultraviolet (UV) light, but erasing takes 20 minutes and reprogramming is done using a dedicated programmer .