.include "/mit/6.004/jsim/nominal.jsim"
.include "/mit/6.004/jsim/lab2checkoff.jsim"

.subckt ORGATE a b o
Xnor a b nor1 NORGATE
Xnot nor1 o NOTGATE
.ends

.subckt NORGATE a b o
M1 midtop a vdd vdd PENH sw=8 sl=1
M2 o b midtop vdd PENH sw=8 sl=1
M3 o a 0 0 NENH sw=8 sl=1
M4 o b 0 0 NENH sw=8 sl=1
.ends

.subckt XORGATE a b o
Xnand a b nor1 NORGATE
M1 midtop a vdd vdd PENH sw=4 sl=1
M2 o nor1 midtop vdd PENH sw=4 sl=1
M3 midbot b 0 0 NENH sw=2 sl=1
M4 o a midbot 0 NENH sw=2 sl=1
M5 midtop b vdd vdd PENH sw=4 sl=1
M6 o nor1 0 0 NENH sw=2 sl=1
.ends

.subckt NOTGATE a o
M1 o a 0 0 NENH sw=2 sl=1
M2 o a vdd vdd PENH sw=4 sl=1
.ends

.subckt ANDGATE a b o
M1 mid a vdd 0 NENH sw=2 sl=1
M2 o2 b mid 0 NENH sw=2 sl=1
M3 o2 a 0 vdd PENH sw=4 sl=1
M4 o2 b 0 vdd PENH sw=4 sl=1
Xnot1 o2 o1 NOTGATE
Xnot2 o1 o NOTGATE
.ends

.subckt FA a b c0 s c1
XXOR1 a b xout XORGATE
XXOR2 xout c0 s XORGATE
XOR1 a b oout ORGATE
XAND1 c0 oout aaut ANDGATE
XAND2 a b aout ANDGATE
XOR2 aaut aout c1 ORGATE
.ends

.subckt adder4 a3 a2 a1 a0 b3 b2 b1 b0 s4 s3 s2 s1 s0
Xbit0 a0 b0 0 s0 c0 FA
Xbit1 a1 b1 c0 s1 c1 FA
Xbit2 a2 b2 c1 s2 c2 FA
Xbit3 a3 b3 c2 s3 s4 FA
.ends

.plot Xtest.s0
.plot Xtest.c0
.plot Xtest.a0
.plot Xtest.b0