About the 8 bit 1.5bit/stage pipelined adc

[kklljim]

hi! all~
i want to ask the questions about the pipelined adc's FFT calcculate for
SNR SNDR
i try to see many papers,but never see the detail calculate way,
just only see some like that:

(1) SNDR=power of signal/(noise + distortion) or
SNDR=signal(db)-noise(db)-distortion(db)
(2) SFDR=power of signal/(max distortion)
(3) SNR=signal(db)-noise(db)

is that could from the picture to observe the approximate result snr sndr?
ex from (3)my sim result max signal is -5db the noise floor is approximate -20db
use the (3) SNR=signal(db)-noise(db) the answer is 15db...........>< it's wrong
i just know how to abserve the SFDR that's

http://www.wretch.cc/album/show.php?i=kklljim&b=1&f=1782284193&p=0
the SFDR si clear to see

and my sim result is (use hspice)

http://www.wretch.cc/album/show.php?i=kklljim&b=1&f=1782284194&p=1

sample rate is 50e6
input is 1e6
.param fs=50e6
.param Ts='1/fs'
.param Trf='0.001*Ts'
.param Tw='0.5*(Ts-2*Trf)'
.param Td='0.5*Ts'
.param NP=1024
.param start=1U
.param Tp=Ts*NP+start

.TRAN Ts Tp

now i don't know how to calculate the snr ,sndr
i guess from hspice's sim data .ft1 or .lis to calculate
but ihave no way to do

this is .ft1' result

erved. 0
2 134 135 hertz pdBar((v(bin1)*1
ppar((v(bin1)*12$&%# 2 134 135 hertz pdBar((v(bin1)*1
0.00000E+000.00000E+000.00000E+000.16276E+05-.47109E+020.26743E+010.32552E+05
-.45440E+020.43290E+010.48828E+05-.46024E+02-.13149E+020.65104E+05-.47558E+02

this is .lis' result

frequency frequency fft_mag fft_mag fft_phase
index (hz) (db) (deg)

1 16.2760k -4.6062 588.4256m -179.8968
2 32.5521k -20.4901 94.5135m 811.7480m
3 48.8281k -54.1494 1.9612m -85.3862
4 65.1042k -54.8149 1.8166m 101.2440
5 81.3802k -59.1118 1.1077m -99.4011
6 97.6562k -60.7478 917.5040u 25.8767
7 113.9323k -71.9040 253.9815u -11.9491