Design and Development of Memory Scrambling Checker and Improvement in Memory Characterization Flow for Advanced Technology Nodes

Abstract

Semiconductor Memories are circuits that store digital information in large quantity, hence are vital subsystem in modern integrated circuits. The ever-increasing demand for low priced memories with low power consumption, high speed operation, high density and small package size has driven the fabrication technology and memory development towards more compact design rules and consequently towards higher data storage densities. The objective is to study the architecture, working and characterization of SRAM memory and also to design the memory scrambling checker with fast spice simulator migration.

Memory Scrambling Checker (MSC) calculates the scrambling equations of memory. There is difference between logical and actual locations of memory cells in memory. So to validate both addresses, MSC is used. It gives the coordinates of particular memory cell in output file. MSC was run on spice simulator till now, but for shrinking technologies other spice simulator migration was required. So during the training MSC has been migrated to other spice simulator. Also old tasks are modified and new ones are added internally in MSC to prevent running simulation on entire core and save time. There are changes, done in the setup of Characterization tool. These changes were done to make the characterization process fast so that the end results are sent to the customer in short duration. This is an important step for convincing the customer to use a memory manufactured in STM by providing the memories parameters according to the specification provided by customer.

Characterization of memory means to get information about its behaviour in terms of different timing access time, setup time, hold time etc), power (dynamic, static and leakage) and capacitances. This will help in evaluating the performance of memory and improves upon the design. The tool used for characterization is Memory Characterization Flow (MCF). Circuit checker (CCK) is extremely flexible and powerful EDA solution to tackle circuit verification demands. CCK tool profiling is also done.