VHDL project topics

hello guys Im an electrical engineer from India. I am required to learn and do projects for my adviser using VHDL. I have been studying VHDL for about a month now but im having difficulty finding a suitable project topic to start my works on. If anyone can give me some idea it would be really helpful guys. Cheers.

plz give me output of comparator output. i have given the code of comparator in spice but there having error plz solve this problem.
program is in hspice.

****comparator*******
.options nomod node list brief POST ingold=1
.option scale=1u
.global control
.param pvdd=5

*****Power Supply********
VDD VDD 0 DC 5
Vp vp 0 DC 2.5 PULSE 2.46 2.54 125n 0 0 10n
vm vm 0 DC 2.5
vss vss 0 dc -5v

M1 n1 vp vss 0 NMOS L=1 W=10
M2 n2 vm vss 0 NMOS L=1 W=10
Ma vss vbiasn 0 0 NMOS L=2 W=20
M31 n1 n1 vdd vdd PMOS L=1 W=20
M41 n2 n2 vdd vdd PMOS L=1 W=20
M3 vop n1 vdd vdd PMOS L=1 W=20
M4 vom n2 vdd vdd PMOS L=1 W=20
M5 vop vop vc 0 NMOS L=1 W=10
M6 vop vom vc 0 NMOS L=1 W=10
M7 vom vop vc 0 NMOS L=1 W=10
M8 vom vom vc 0 NMOS L=1 W=10
Mb vc vc 0 0 NMOS L=10 W=10
M9L n4 vom n3 0 NMOS L=1 W=10
M9R vdo vop n3 0 NMOS L=1 W=10
M10L n4 n4 vdd vdd PMOS L=1 W=20
M10R vdo n4 vdd vdd PMOS L=1 W=20
Mc n3 n4 0 0 NMOS L=1 W=10
MIN out vdo 0 0 NMOS L=1 W=10
MIP out vdo vdd vdd PMOS L=1 W=20
.subckt bias vbiasn vbiasp VDD
M1 Vbiasn Vbiasn 0 0 NMOS L=2 W=10
M2 Vbiasp Vbiasn Vr 0 NMOS L=2 W=40
M3 Vbiasn Vbiasp VDD VDD PMOS L=2 W=30
M4 Vbiasp Vbiasp VDD VDD PMOS L=2 W=30
Rbias Vr 0 6.5k
MSU1 Vsur Vbiasn 0 0 NMOS L=2 W=10
MSU2 Vsur Vsur VDD VDD PMOS L=100 W=10
MSU3 Vbiasp Vsur Vbiasn 0 NMOS L=1 W=10


******TRANSIENT*******
.tran 100p 150n

.meas max_power max power
.measure TRAN risetime TRIG v(out) VAL='0.1*pvdd' rise=1 TARG V(out) VAL='0.9*pvdd' rise=1
.measure TRAN falltime TRIG v(out) VAL='0.9*pvdd' fall=1 TARG V(out) VAL='0.1*pvdd' fall=1

.lib 'E:\Spice_example\tsmccl013g_logic.spice' TT
.end
.include .\1um_models.txt
.end