Semiconductor Memories Designs And Applications

Semiconductor storage on a chip is an indispensable part in SOC, and its performance will impact greatly on the chip's area and the system's function . As the scale of the VLSI is being more and more larger, and its function more and more complex, the importance of semiconductor storage on a chip deserves more attention. In this paper, we will focus on these。A 32KB Static Random Access Memory (SRAM), which is widely used at present in VLSI, is designed in this paper. To speed up the accessing process and reduce the power consuming, we optimize the structure of the memory and latch-up sense amplifier is adopted. The layout is designed based on the 0.35um technology. Simulation of layout in SPICE is very different, because the layout contains a huge number of parameters. A simulation model of SRAM is brought out in this paper, with the purpose of speeding up the simulation as well as ensuring the precision.Holding the data in SRAM when accident power-down is very important in many industrial applications. To solve this problem, two NVSRAM with different structures are designed, which is based on the fundamental that EEPROM storage the data on SRAM at accident power-down. In the first one, a new memory cell which is comprised of SRAM cell and EEPROM cell is designed. And the second design is based on the parallelism of the SRAM array and the EEPROM array. Key modules in the two NVSRAM are simulated and their performance is verified. In the end, layouts of them are designed with the 0.35um technology including high-voltage and normal-voltage condition.