SPICE netlist for D flip - flop

LTSPice has a DFlop in its libs.

Down load LTspice and play with it..

Working, by what criteria? Do you just want output slew rates and/or skew? Do you want to explore metastability? Spice can handle the first, but not easily the second.

I am more concerned about the metastability - in fact, have tried several designs, e.g., ratioless enhancement mode NMOS. The D flip flop works in that I can see the nice Q and Qb signals but problem starts as soon as I put it in a feedback loop, e.g., connect Qb to the D input

- 1 bit counter, things go haywire, even with initializing the Q and Qb lines.

If you wish to explore realistic ones, look at the .NODESET spice directive, and be sure to terminate all inputs.

Here you go. 5V with all handles. You'll need to provide models for MODN and MODP. I'm bound by NDA not to give out that information. Watch out for line-wrapping screwing up line continuity.

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• D-FLOP with Q, QN & Reset(NOT) & Set(NOT), Positive Edge Clock Triggered .SUBCKT DFULL C D Q QN RN SN VP VN Mn13 NETZ111 SN VN VN MODN W=2u L=600n M=1 AD=3e-12 AS=3e-12 PD=5u PS=5u

+NRD=0.4 NRS=0.4 Mn14 SQI SQIB NETZ111 VN MODN W=800.0n L=600n M=1 AD=1.2e-12 AS=1.2e-12 +PD=3.8u PS=3.8u NRD=1 NRS=1 Mn10 SQIB CIB NETZ123 VN MODN W=800.0n L=600n M=1 AD=1.2e-12 AS=1.2e-12 +PD=3.8u PS=3.8u NRD=1 NRS=1 Mn11 NETZ123 SQI NETZ136 VN MODN W=800.0n L=600n M=1 AD=1.2e-12 AS=1.2e-12 +PD=3.8u PS=3.8u NRD=1 NRS=1 Mn12 NETZ136 RN VN VN MODN W=1.1u L=600n M=1 AD=1.65e-12 AS=1.65e-12 +PD=4.1u PS=4.1u NRD=0.727273 NRS=0.727273 Mn8 SQIB CI NETZ135 VN MODN W=800.0n L=600n M=1 AD=1.2e-12 AS=1.2e-12 +PD=3.8u PS=3.8u NRD=1 NRS=1 Mn9 NETZ135 MQI NETZ136 VN MODN W=800.0n L=600n M=1 AD=1.2e-12 AS=1.2e-12 +PD=3.8u PS=3.8u NRD=1 NRS=1 Mn7 NETZ139 SN VN VN MODN W=2u L=600n M=1 AD=3e-12 AS=3e-12 PD=5u PS=5u +NRD=0.4 NRS=0.4 Mn6 MQI MQIB NETZ139 VN MODN W=800.0n L=600n M=1 AD=1.2e-12 AS=1.2e-12 +PD=3.8u PS=3.8u NRD=1 NRS=1 Mn4 MQIB CI NETZ151 VN MODN W=800.0n L=600n M=1 AD=1.2e-12 AS=1.2e-12 +PD=3.8u PS=3.8u NRD=1 NRS=1 Mn3 NETZ151 MQI NETZ164 VN MODN W=800.0n L=600n M=1 AD=1.2e-12 AS=1.2e-12 +PD=3.8u PS=3.8u NRD=1 NRS=1 Mn5 NETZ164 RN VN VN MODN W=2u L=600n M=1 AD=3e-12 AS=3e-12 PD=5u PS=5u +NRD=0.4 NRS=0.4 Mn1 MQIB CIB NETZ163 VN MODN W=800.0n L=600n M=1 AD=1.2e-12 AS=1.2e-12 +PD=3.8u PS=3.8u NRD=1 NRS=1 Mn2 NETZ163 D NETZ164 VN MODN W=800.0n L=600n M=1 AD=1.2e-12 AS=1.2e-12 +PD=3.8u PS=3.8u NRD=1 NRS=1 Mp13 SQI SN VP VP MODP W=1.1u L=600n M=1 AD=1.65e-12 AS=1.65e-12 PD=4.1u +PS=4.1u NRD=0.727273 NRS=0.727273 Mp12 SQIB RN VP VP MODP W=1.1u L=600n M=1 AD=1.65e-12 AS=1.65e-12 +PD=4.1u PS=4.1u NRD=0.727273 NRS=0.727273 Mp14 SQI SQIB VP VP MODP W=1.1u L=600n M=1 AD=1.65e-12 AS=1.65e-12 +PD=4.1u PS=4.1u NRD=0.727273 NRS=0.727273 Mp10 SQIB CI NETZ179 VP MODP W=800.0n L=600n M=1 AD=1.2e-12 AS=1.2e-12 +PD=3.8u PS=3.8u NRD=1 NRS=1 Mp8 SQIB CIB NETZ183 VP MODP W=1.1u L=600n M=1 AD=1.65e-12 AS=1.65e-12 +PD=4.1u PS=4.1u NRD=0.727273 NRS=0.727273 Mp9 NETZ183 MQI VP VP MODP W=1.1u L=600n M=1 AD=1.65e-12 AS=1.65e-12 +PD=4.1u PS=4.1u NRD=0.727273 NRS=0.727273 Mp11 NETZ179 SQI VP VP MODP W=800.0n L=600n M=1 AD=1.2e-12 AS=1.2e-12 +PD=3.8u PS=3.8u NRD=1 NRS=1 Mp7 MQI SN VP VP MODP W=1.1u L=600n M=1 AD=1.65e-12 AS=1.65e-12 PD=4.1u +PS=4.1u NRD=0.727273 NRS=0.727273 Mp5 MQIB RN VP VP MODP W=1.1u L=600n M=1 AD=1.65e-12 AS=1.65e-12 PD=4.1u +PS=4.1u NRD=0.727273 NRS=0.727273 Mp6 MQI MQIB VP VP MODP W=1.1u L=600n M=1 AD=1.65e-12 AS=1.65e-12 +PD=4.1u PS=4.1u NRD=0.727273 NRS=0.727273 Mp4 MQIB CIB NETZ207 VP MODP W=800.0n L=600n M=1 AD=1.2e-12 AS=1.2e-12 +PD=3.8u PS=3.8u NRD=1 NRS=1 Mp3 NETZ207 MQI VP VP MODP W=800.0n L=600n M=1 AD=1.2e-12 AS=1.2e-12 +PD=3.8u PS=3.8u NRD=1 NRS=1 Mp1 MQIB CI NETZ215 VP MODP W=1.1u L=600n M=1 AD=1.65e-12 AS=1.65e-12 +PD=4.1u PS=4.1u NRD=0.727273 NRS=0.727273 Mp2 NETZ215 D VP VP MODP W=1.1u L=600n M=1 AD=1.65e-12 AS=1.65e-12 +PD=4.1u PS=4.1u NRD=0.727273 NRS=0.727273 XIN_4 SQI QN VN VP INVR PARAMS: GT_PUL=600n GT_PUW=3.0u +LC=800n SX=1.5u GT_PDL=600n GT_PDW=1.5u XIN_3 SQIB Q VN VP INVR PARAMS: GT_PUL=600n GT_PUW=3.0u +LC=800n SX=1.5u GT_PDL=600n GT_PDW=1.5u XIN_2 CIB CI VN VP INVR PARAMS: GT_PUL=600n GT_PUW=1.1u +LC=800n SX=1.5u GT_PDL=600n GT_PDW=0.8u XIN_1 C CIB VN VP INVR PARAMS: GT_PUL=600n GT_PUW=1.1u +LC=800n SX=1.5u GT_PDL=600n GT_PDW=0.8u .ENDS DFULL ************************************************************************ ...Jim Thompson

Ooooops! Left out a needed subcircuit. Repost...

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• D-FLOP with Q, QN & Reset(NOT) & Set(NOT), Positive Edge Clock Triggered .SUBCKT DFULL C D Q QN RN SN VP VN Mn13 NETZ111 SN VN VN MODN W=2u L=600n M=1 AD=3e-12 AS=3e-12 PD=5u PS=5u

+NRD=0.4 NRS=0.4 Mn14 SQI SQIB NETZ111 VN MODN W=800.0n L=600n M=1 AD=1.2e-12 AS=1.2e-12 +PD=3.8u PS=3.8u NRD=1 NRS=1 Mn10 SQIB CIB NETZ123 VN MODN W=800.0n L=600n M=1 AD=1.2e-12 AS=1.2e-12 +PD=3.8u PS=3.8u NRD=1 NRS=1 Mn11 NETZ123 SQI NETZ136 VN MODN W=800.0n L=600n M=1 AD=1.2e-12 AS=1.2e-12 +PD=3.8u PS=3.8u NRD=1 NRS=1 Mn12 NETZ136 RN VN VN MODN W=1.1u L=600n M=1 AD=1.65e-12 AS=1.65e-12 +PD=4.1u PS=4.1u NRD=0.727273 NRS=0.727273 Mn8 SQIB CI NETZ135 VN MODN W=800.0n L=600n M=1 AD=1.2e-12 AS=1.2e-12 +PD=3.8u PS=3.8u NRD=1 NRS=1 Mn9 NETZ135 MQI NETZ136 VN MODN W=800.0n L=600n M=1 AD=1.2e-12 AS=1.2e-12 +PD=3.8u PS=3.8u NRD=1 NRS=1 Mn7 NETZ139 SN VN VN MODN W=2u L=600n M=1 AD=3e-12 AS=3e-12 PD=5u PS=5u +NRD=0.4 NRS=0.4 Mn6 MQI MQIB NETZ139 VN MODN W=800.0n L=600n M=1 AD=1.2e-12 AS=1.2e-12 +PD=3.8u PS=3.8u NRD=1 NRS=1 Mn4 MQIB CI NETZ151 VN MODN W=800.0n L=600n M=1 AD=1.2e-12 AS=1.2e-12 +PD=3.8u PS=3.8u NRD=1 NRS=1 Mn3 NETZ151 MQI NETZ164 VN MODN W=800.0n L=600n M=1 AD=1.2e-12 AS=1.2e-12 +PD=3.8u PS=3.8u NRD=1 NRS=1 Mn5 NETZ164 RN VN VN MODN W=2u L=600n M=1 AD=3e-12 AS=3e-12 PD=5u PS=5u +NRD=0.4 NRS=0.4 Mn1 MQIB CIB NETZ163 VN MODN W=800.0n L=600n M=1 AD=1.2e-12 AS=1.2e-12 +PD=3.8u PS=3.8u NRD=1 NRS=1 Mn2 NETZ163 D NETZ164 VN MODN W=800.0n L=600n M=1 AD=1.2e-12 AS=1.2e-12 +PD=3.8u PS=3.8u NRD=1 NRS=1 Mp13 SQI SN VP VP MODP W=1.1u L=600n M=1 AD=1.65e-12 AS=1.65e-12 PD=4.1u +PS=4.1u NRD=0.727273 NRS=0.727273 Mp12 SQIB RN VP VP MODP W=1.1u L=600n M=1 AD=1.65e-12 AS=1.65e-12 +PD=4.1u PS=4.1u NRD=0.727273 NRS=0.727273 Mp14 SQI SQIB VP VP MODP W=1.1u L=600n M=1 AD=1.65e-12 AS=1.65e-12 +PD=4.1u PS=4.1u NRD=0.727273 NRS=0.727273 Mp10 SQIB CI NETZ179 VP MODP W=800.0n L=600n M=1 AD=1.2e-12 AS=1.2e-12 +PD=3.8u PS=3.8u NRD=1 NRS=1 Mp8 SQIB CIB NETZ183 VP MODP W=1.1u L=600n M=1 AD=1.65e-12 AS=1.65e-12 +PD=4.1u PS=4.1u NRD=0.727273 NRS=0.727273 Mp9 NETZ183 MQI VP VP MODP W=1.1u L=600n M=1 AD=1.65e-12 AS=1.65e-12 +PD=4.1u PS=4.1u NRD=0.727273 NRS=0.727273 Mp11 NETZ179 SQI VP VP MODP W=800.0n L=600n M=1 AD=1.2e-12 AS=1.2e-12 +PD=3.8u PS=3.8u NRD=1 NRS=1 Mp7 MQI SN VP VP MODP W=1.1u L=600n M=1 AD=1.65e-12 AS=1.65e-12 PD=4.1u +PS=4.1u NRD=0.727273 NRS=0.727273 Mp5 MQIB RN VP VP MODP W=1.1u L=600n M=1 AD=1.65e-12 AS=1.65e-12 PD=4.1u +PS=4.1u NRD=0.727273 NRS=0.727273 Mp6 MQI MQIB VP VP MODP W=1.1u L=600n M=1 AD=1.65e-12 AS=1.65e-12 +PD=4.1u PS=4.1u NRD=0.727273 NRS=0.727273 Mp4 MQIB CIB NETZ207 VP MODP W=800.0n L=600n M=1 AD=1.2e-12 AS=1.2e-12 +PD=3.8u PS=3.8u NRD=1 NRS=1 Mp3 NETZ207 MQI VP VP MODP W=800.0n L=600n M=1 AD=1.2e-12 AS=1.2e-12 +PD=3.8u PS=3.8u NRD=1 NRS=1 Mp1 MQIB CI NETZ215 VP MODP W=1.1u L=600n M=1 AD=1.65e-12 AS=1.65e-12 +PD=4.1u PS=4.1u NRD=0.727273 NRS=0.727273 Mp2 NETZ215 D VP VP MODP W=1.1u L=600n M=1 AD=1.65e-12 AS=1.65e-12 +PD=4.1u PS=4.1u NRD=0.727273 NRS=0.727273 XIN_4 SQI QN VN VP INVR PARAMS: GT_PUL=600n GT_PUW=3.0u +LC=800n SX=1.5u GT_PDL=600n GT_PDW=1.5u XIN_3 SQIB Q VN VP INVR PARAMS: GT_PUL=600n GT_PUW=3.0u +LC=800n SX=1.5u GT_PDL=600n GT_PDW=1.5u XIN_2 CIB CI VN VP INVR PARAMS: GT_PUL=600n GT_PUW=1.1u +LC=800n SX=1.5u GT_PDL=600n GT_PDW=0.8u XIN_1 C CIB VN VP INVR PARAMS: GT_PUL=600n GT_PUW=1.1u +LC=800n SX=1.5u GT_PDL=600n GT_PDW=0.8u .ENDS DFULL ************************************************************************ ************************************************************************ .SUBCKT INVR IN OUT VN VP PARAMS: GT_PUL=600n GT_PUW=2u LC=800n +SX=1.5u GT_PDL=600n GT_PDW=1.1u MMN1 OUT IN VN VN MODN W={GT_PDW} L={GT_PDL} M=1 +AD={SX*(GT_PDW)} AS={SX*(GT_PDW)} PD={2*SX+(GT_PDW)} PS={2*SX+(GT_PDW)} +NRD={LC/(GT_PDW)} NRS={LC/(GT_PDW)} MMP1 OUT IN VP VP MODP W={GT_PUW} L={GT_PUL} M=1 +AD={SX*(GT_PUW)} AS={SX*(GT_PUW)} PD={2*SX+(GT_PUW)} PS={2*SX+(GT_PUW)} +NRD={LC/(GT_PUW)} NRS={LC/(GT_PUW)} .ENDS INVR ************************************************************************ ...Jim Thompson