IC697MEM735  | 32位CMOS扩展存储器  增加芯片以扩充容量

品牌： GE发那科

系列 ：90-70系列

零件编号 ：IC697MEM735

类型 ：32位CMOS扩展存储器

保质期： 20 摄氏度（68 华氏度）下 10 年

记忆保持： 6 个月标称无外加电源

兼容的： CPU 780、781、782、788 和 789 CPU

用于安装的附加插槽 ：不需要

锂电池： 支持

额定值： VME 标准

IC697MEM735 扩展存储器主要是通过增加存储芯片的数量来扩大存储容量，因为单片存储芯片的容量有限，难以满足实际需求。扩展存储器的方式主要有位扩展和字扩展两种，以及字位都扩展的情况。

位扩展：在位扩展中，需要将多个存储芯片的位数相加，以增加数据线的数量。这样，两个芯片共用相同的片选信号，同时被选中，每个芯片进行读或写一定位数的数据，两个芯片合在一起就是更高位数的数据。

字扩展：IC697MEM735字扩展是在字数方向上扩展，即在芯片位数不变的情况下，增加芯片以扩充容量。这主要涉及到地址线的连接、读写信号的连接以及芯片的地址范围等问题。

字位都扩展：这是同时考虑位扩展和字扩展的情况，根据实际需求同时增加存储芯片的位数和数量。

对于具体的实现方式，如51单片机等特定设备，其扩展存储器的方式可能有所不同。例如，在51单片机中，因为取指令和取数据是分开进行的，所以可以共用地址线而不起冲突。在扩展时，特定的端口（如P0口和P2口）可以作为地址线，同时还需要考虑地址锁存器等因素。

Brand: GE Fanuc

Series: 90-70 series

Part number: IC697MEM735

Type: 32-bit CMOS extended memory

Shelf life: 10 years at 20 degrees Celsius (68 degrees Fahrenheit)

Memory retention: 6 months nominal no external power supply

Compatible: CPU 780, 781, 782, 788, and 789 cpus

Additional slot for installation: not required

Lithium battery: Supported

Rating: VME standard

IC697MEM735 extended memory is mainly to expand the storage capacity by increasing the number of memory chips, because the capacity of a single memory chip is limited, it is difficult to meet the actual needs. There are two main ways to expand memory: bit expansion and word expansion, and the case of both word and bit expansion.

Bit expansion: In in-place expansion, the bits of multiple memory chips need to be added together to increase the number of data lines. In this way, two chips share the same chip selection signal and are selected at the same time, each chip reads or writes a certain number of bits of data, and the two chips together are higher bits of data.

Word expansion: IC697MEM735 word expansion is in the direction of word expansion, that is, in the case of constant chip bits, increase the chip to expand the capacity. This mainly involves the connection of the address line, the connection of the read and write signal and the address range of the chip.

Word and bit expansion: This is to consider the case of bit expansion and word expansion at the same time, and increase the number of bits and the number of memory chips according to actual needs.

For specific implementation methods, such as specific devices such as 51 single chip computers, the way of expanding memory may be different. For example, in 51 MCU, because fetching instructions and fetching data are carried out separately, the address line can be shared without conflict. When scaling, specific ports (such as P0 and P2) can be used as address lines, while also taking into account factors such as address latches.