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#sky130
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# sky130
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Binoy B

03/23/2022, 12:28 PM
Hi, I have found reram in sky130B . So I can draw a rectangle and use paint reram command in magic to get one. But there is a doubt regarding taking connections. Is it like, from one side of reram I connect a metal 1 layer through via and and on the other side I connect metal2 through via? Please give suggestions.
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Tim Edwards

03/23/2022, 12:58 PM
The ReRAM device drawn in magic is a combination of the ReRAM and VIA layers. You just need to connect to it with metal1 and metal2. In magic, the ReRAM will be shown as connected to metal2 but not metal1, but it will be extracted as a device connected between metal1 and metal2.
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Harald Pretl

03/23/2022, 4:59 PM
@User Is the ReRAM device documented? Especially the electric spec would be really interesting.
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Binoy B

03/23/2022, 5:03 PM
@User I have created a simple reram array layout in magic and corresponding netlist is simulated using ngspice. I get the following error...'unknown subckt: x0 out2 in2 sky130_fd_pr__reram_reram_cell area_ox=4770'
I have actually included the subcircuit definition in netlist.........* SPICE3 file created from testarray.ext - technology: sky130B .subckt sky130_fd_pr_reram__reram_cell BE TE R0 BE TE 0.000000 .ends .option scale=10000u X0 out2 in2 sky130_fd_pr__reram_reram_cell area_ox=4770 X1 out1 in2 sky130_fd_pr__reram_reram_cell area_ox=6039 X2 out2 in1 sky130_fd_pr__reram_reram_cell area_ox=3655 X3 out1 in1 sky130_fd_pr__reram_reram_cell area_ox=3774 vin in1 in2 pwl (0 0 10ms 0 11ms 5v 20ms 5v) *transient analysis for 20ms, step size 0.02ms .tran 0.02ms 20ms *defining the run-time control functions .control run *plotting input and output voltages plot v(out1) v(out2) .endc .end
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Tim Edwards

03/23/2022, 5:18 PM
@User: Simulation will be problematic because there is no SPICE model for the ReRAM device. There is a verilog-AMS model, but using it in ngspice requires it to be compiled into the ngspice executable itself. I have not attempted that myself. It should be a bit easier to do in Xyce, which allows plug-in objects for verilog-AMS modules. I haven't tried that myself, either.
@User, @User: This link from Tim Ansell is the best reference I've seen for the ReRAM device: https://sky130-fd-pr-reram.readthedocs.io/en/latest/technology_specifications.html#forming
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Harald Pretl

03/23/2022, 6:07 PM
Thanks, that is helpful!