Three large capacity, high speed nonvolatile SRAM contrast

 

At present, the large capacity that are widely used in the high-speed nonvolatile SRAM has the following kinds:

1, NVSRAM, is a kind of twin hull structure non-volatile SRAM, the internal memory contains two memory: one is for users to read and write ordinary SRAM, the other one is the same as the capacity of SRAM, block for data backup EEPROM (or Quantum Trap).Under normal working state, visited the NVSRAM, microprocessor, the operation is an SRAM, only when the power outage, block automatically backup the content of SRAM is fast to EEPROM chip (or Quantum Trap), the content will not be lost;In the next time power supply, electric, it block the EEPROM in the backup content automatic recovery in the SRAM.Large capacity NVSRAM typically have a Cypress CY14B104 (512 kx8/256 kx16), CY14B108 (1 mx8/512 kx16), read and write cycles as high as 20 ns.This chip has a small defect is a must to external a high-capacity capacitor, used for electrical backup data buffer power supply.In addition, in the domestic market is not easy to buy.

2, FRAM, ferroelectric memory ".Its core technology is ferroelectric crystal material.This special material makes ferroelectric memory also has the characteristics of the RAM and ROM.Each free floating in the crystal array atoms only two stable states, one for memory logic "0", another to memory logic "1".State data can keep the more than 100 years.FRAM products have a series of super properties.For example, the random read/write access time (only 55 ns),

 

Ultra-low power consumption (1/2500) block only EEPROM and almost infinite time to read and write cycles (up to 10 of 14 times).RAMTRON company is the invention of the FRAM and producers, the large volume of currently available models;FM21L16 (256 kx8/128 kx16), FM22L16 (512 kx16 kx8/256).Unlike NVSRAM, FRAM data is synchronized with the backup, so there is no recovery operations.

3, MRAM, namely "reluctance RAM", Freescale is the company's patented product, USES the magnetic tunnel junction (MTJ) structure for data storage.MRAM use of magnetic materials and traditional silicon circuit in a single device provides high speed SRAM and non-volatile flash memory, its life is almost no limit.MRAM devices, configuration can be used for high-speed buffer memory and other demands high-speed, durable and non-volatile commercial applications.The present product model includes: MR0A16 ~ MR2A16, capacity of: 128 kx8/64 kx16 ~ 512 kx8/256 kx16, read/write cycle of 35 ns.

It is important to note that due to the structure of RAM, FRAM and MRAM pin is fully compatible with, external capacitance NVRAM any pin and address line number is different, if processor by FPGA and its connected can redefine), basic compatible.

 

 

 

key words: SRAM