How to plot butterfly curve of SRAM?

How to plot Butterfly curve of SRAM cell in Cadence tool – Quora. Setup your SRAM back to back intverts in schematic. On one of the inverter input attache a DC voltage source and assign the DC voltage to a name instead of a value for DC sweep.

How do you calculate SNM of SRAM?

In order to find the SNM of the cell, you can measure the side lengths (not diagonal lengths!) of both of these squares, and the smaller of the two lengths is the SNM of the SRAM cell.

What’s the pull up ratio in 6T SRAM?

-> pulldown (PD) should of minimum size. ->pullup (PU) should be around 0.7-0.8 times of PG.

What is write margin in SRAM?

Write margin is the measure of the ability to write data into the SRAM cell. Write margin voltage is the maximum noise voltage present at bit lines during successful write operation. When noise voltages exceeds the write margin voltage, then write failure occurs.

What is 8T SRAM cell?

The 8T-SRAM cell provides significantly improved RSNM (similar to the Hold Static Noise Margin (HSNM) of the standard 6T-SRAM cell) with similar access time, write time, and write margin. However, for the 8T-SRAM cell write assist techniques such as boosted wordline without affecting the read performance can be used.

What is SNM in SRAM?

Static Noise Margin (SNM) is the most important parameter for memory design. SNM, which affects both read and write margin, is related to the threshold voltages of the NMOS and PMOS devices of the SRAM cell that is why we have analyzed SNM with the Read Margin, Write Margin and also the Threshold voltage.

What is read margin in SRAM?

A good metric for read/write margin is critically important to all kinds of SRAM designs. SNM is defined as the minimum DC noise voltage [2] needed to flip the cell state, and is used to quantify the stability of a SRAM cell using a static approach.

How many transistors are there in 6T SRAM?

Two additional access transistors serve to control the access to a storage cell during read and write operations. In addition to such six-transistor (6T) SRAM, other kinds of SRAM chips use 4, 8, 10 (4T, 8T, 10T SRAM), or more transistors per bit.

How do you plot VOUT or VIN in cadence?

Click and drag the “VS(“/vout”) curve onto the VS(“/vin”) curve and you should have a plot similar to the one in figure 3. Using the Crosshair marker icon, find the value for vdc that corresponds to the maximum magnitude of the slope.