Memory cells basic documents

[Prathibha Rao]

Hi,

I wish to learn about memory cells in vlsi,
can anybody send me the basic documents which you referred before?

Regards,
P.R

 

[erikl]

Which one? ROM, RAM, SRAM, DRAM, FRAM, MRAM, FUSE cells?

 

[Prathibha Rao]

Hi,

I am a fresher to memory layout and which one is good to learn in starting stage? I think SRAM and DRAM, is I am correct?

Regards,
P.R

 

[Darshan_Dhameliya]

Hello Sir,

Even I want knowledge about Flash memory and how to implement(direct layout or schematic then layout) and I have tanner v.13 *****.

Thank you & Regards
Darshan

 

[velkumargn]

SRAM 6-T is enough

 

[velkumargn]

Hi,

before going with full architecture level of SRAM, first do BITCELL analysis, and SENSE Amp analysis. they both will help you to understand how memory works , then you can move to timing,power area for SRAM .

IN BIT CELL analysis you need to do

1) SNM ( Static noise margin -read disturbance margin) 2) write margin 3)Ion 4)Ioff 5) I leak 6)retention voltage

In SENSE sense amp u can go with current based or voltage based .

mostly Latch type used in SRAM

so you need to go with Latch type sense amp, in that 1) 0- offset, 1-offcet, 3) voltage Difference....

Just you can try in google like SNM in SRAM, write margin in SRAM , you will get lot of link to get knowledge

 

[Darshan_Dhameliya]

Thank you sir

Sir i have few question..

1) which software i can use...? I have tanner v13.0 and mentor graphics
2) Is there any architecture is available of BIT CELL & SENSE amp And 6-T SRAM.? So i can use directly that architecture.
3) Can you send me URL or any video tutorial link..?

Thank you & Regards
Darshan

 

[velkumargn]

1) there is lot of freeware available in Google itself.

a) for simulation LTspice, ngspice, ORDAD student version,.....like this n number of tools available.

You ask which technology it support ?

this tools will support for all technology which you have.

I can say one way to get technology files .U can generate all tech from http://ptm.asu.edu/

go to post-silicon select device nmos or pmos 32nm, 45nm, 65nm, 90nm, 130nm. I try to go with at least 45nm. since I know 28nm, 20nm,45nm, for older tech I cant help you out.

now model is ready with you for SS, SF, FS, FF,NN(TT).

If you have Mentor- graphics simulation tool that's good one, ask your guide to how to use it. but technology u need to think.

For layout also u get http://www.peardrop.co.uk/

for this tool 130nm already available for DRC, LVS check with tool itself , for 45nm,28nm,20nm I ll send the DRM for you which I have created , even you can try ur own technology files.

2) Just type in google as 6T bitcell analysis. that is basic version for SRAM cell. all the paper will give correct explanations . No need of worry for architecture.

3)I have some book(pdf) for memory. but it in my country. now am in on-site.

u just Google it ? as SNM , write margin in SRAM.

 

[Darshan_Dhameliya]

Sir in http://ptm.asu.edu/ >> Nano-CMOS>> NMOS (45nm) selected but about these value..? Its predefined value.

Leff 17.5nm
Vth 0.18 V
Vdd 1V
Tox 1.1nm
Rdsw 155Ohm

so How to choose..?
Sir, in Mentor graphic how to check which technology is available...? because my doesn't know..

Can you send DRAM....? Its really help for design SRAM and its sense amp and other connection.....

Thank you & Regards
Darshan

 

[velkumargn]

use the values same .