* sw ring-oscillators

.control
destroy all
run
plot I(vmeasurea) I(vmeasureb) I(vmeasurec) I(vmeasured)
plot V(outa) V(outb) V(outc) V(outd)
rusage 
.endc

.tran 3m 3

VDD VDD2 0 DC 3
Rla VDD2 outa 1k
Rlb VDD2 outb 1k
Rlc VDD2 outc 1k
Rld VDD2 outd 1k

VMEASUREa DGNDa 0 dc 0
VMEASUREb DGNDb 0 dc 0
VMEASUREc DGNDc 0 dc 0
VMEASUREd DGNDd 0 dc 0

Vin in 0 pulse ( 0 3 0 3 3 10 10 )

xsa in outa DGNDa switcha
xsb in outb DGNDb switchb
xsc in outc DGNDc switchc
xsd in outd DGNDd switchd


.subckt switcha In Out DGND
a.xx17.asn %gd in DGND %gd out DGND aswswitch
.model aswswitch pswitch( log=true cntl_on=1.5 cntl_off=2.5 r_on=1k r_off=2g)
.ends

.subckt switchb In Out DGND
a.xx17.asn %gd in DGND %gd out DGND aswswitch
.model aswswitch pswitch( log=true cntl_on=1.5 cntl_off=2.5 r_on=1k r_off=2k)
.ends

.subckt switchc In Out DGND
a.xx17.asn %gd in DGND %gd out DGND aswswitch
.model aswswitch pswitch( log=true cntl_on=2.5 cntl_off=1.5 r_on=1k r_off=2g)
.ends

.subckt switchd In Out DGND
a.xx17.asn %gd in DGND %gd out DGND aswswitch
.model aswswitch pswitch( log=true cntl_on=2.5 cntl_off=1.5 r_on=1k r_off=2k)
.ends

.end