| SRAM 1-bit Cell Read Operation |
| |
| .lib "./libs/models/sky130.lib.spice" tt |
| |
| |
| ****************** 6T SRAM Cell *********************** |
| *** Inverter 1 |
| XM1 q qbar gnd gnd sky130_fd_pr__nfet_01v8 w=0.42 l=0.21 |
| XM2 q qbar vdd vdd sky130_fd_pr__pfet_01v8 w=0.84 l=0.21 |
| |
| *** Inverter 2 |
| XM3 qbar q gnd gnd sky130_fd_pr__nfet_01v8 w=0.42 l=0.21 |
| XM4 qbar q vdd vdd sky130_fd_pr__pfet_01v8 w=0.84 l=0.21 |
| |
| *** Access Transistors |
| XM5 q wl bl gnd sky130_fd_pr__nfet_01v8 w=0.42 l=0.21 |
| XM6 qbar wl blbar gnd sky130_fd_pr__nfet_01v8 w=0.42 l=0.21 |
| |
| ******************** |
| |
| .subckt inv ip op vdd gnd |
| XM1 op ip vdd vdd sky130_fd_pr__pfet_01v8 w=0.84 l=0.21 |
| XM2 op ip gnd gnd sky130_fd_pr__nfet_01v8 w=0.42 l=0.21 |
| .ends inv |
| |
| |
| ***************** Sense Amplifier ********************** |
| XM7 net1 blbar net2 net2 sky130_fd_pr__nfet_01v8 w=0.42 l=0.21 |
| XM8 dout1 bl net2 net2 sky130_fd_pr__nfet_01v8 w=0.42 l=0.21 |
| |
| XM9 net1 net1 vdd vdd sky130_fd_pr__pfet_01v8 w=0.42 l=0.21 |
| XM10 dout1 net1 vdd vdd sky130_fd_pr__pfet_01v8 w=0.84 l=0.21 |
| |
| XM11 net2 rd_en gnd gnd sky130_fd_pr__nfet_01v8 w=1.26 l=0.21 |
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| xinv dout1 dout vdd gnd inv |
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| ***************** Write Driver ************************ |
| .subckt nor_gate in1 in2 out vdd gnd |
| XM1 out in1 gnd gnd sky130_fd_pr__nfet_01v8 w=0.42 l=0.21 |
| XM2 out in2 gnd gnd sky130_fd_pr__nfet_01v8 w=0.42 l=0.21 |
| XM3 out in1 temp vdd sky130_fd_pr__pfet_01v8 w=0.84 l=0.21 |
| XM4 temp in2 vdd vdd sky130_fd_pr__pfet_01v8 w=0.84 l=0.21 |
| .ends nor_gate |
| |
| |
| *Precharge circuit |
| XM14 bl gnd vdd vdd sky130_fd_pr__pfet_01v8 w=0.84 l=0.21 |
| XM15 blbar gnd vdd vdd sky130_fd_pr__pfet_01v8 w=0.84 l=0.21 |
| |
| xinv1 din dinb vdd gnd inv |
| xinv2 dinb dinbb vdd gnd inv |
| xnor1 wr_en dinb out1 vdd gnd nor_gate |
| xnor2 wr_en dinbb out2 vdd gnd nor_gate |
| XM16 blbar out1 gnd gnd sky130_fd_pr__nfet_01v8 w=0.42 l=0.21 |
| XM17 bl out2 gnd gnd sky130_fd_pr__nfet_01v8 w=0.42 l=0.21 |
| |
| ******************************************************* |
| |
| V1 vdd gnd dc 1.8V |
| Vwl wl gnd pulse 0 1.8 0 60ps 60ps 5ns 10ns |
| Vq q gnd pulse 0 1.8 0 60ps 60ps 1ns 2ns |
| Vrd rd_en gnd pulse 0 1.8 0 60ps 60ps 5ns 10ns |
| Vwr_en wr_en gnd dc 1.8V |
| Vdin din gnd dc 0V |
| |
| .tran 0.1p 20n |
| .control |
| run |
| plot V(rd_en)+10 V(dout) V(bl)+4 V(blbar)+2 V(q)+8 V(qbar)+6 |
| |
| .endc |
| .end |
| |
