[quote author=kundert link=1477843044/0#8 date=1478410502]
Quote:Actually I inject 4GhZ Clock generator and it gives me four non overlap clock at 1Ghz
If the inputs are periodic in 1GHz, why are you specifying 4GHz as the fundamental frequency?
input is 4Ghz clcok and output is four nonoverlap clcok at 1Ghz
I even change input frequncy to 1Ghz ,did not converge again
Periodic Steady-State Analysis `pss': fund = 1 GHz
**************************************************
Trying `homotopy = gmin' for initial conditions.
Notice from spectre during IC analysis, during periodic steady state analysis `pss'.
GminDC = 1 pS is large enough to noticeably affect the DC solution.
dV(I0.I171|I1|T3:int_d) = -93.7384 mV
Use the `gmin_check' option to eliminate or expand this report.
Bad pivoting is found during DC analysis. Option dc_pivot_check=yes is recommended for possible improvement of convergence.
DC simulation time: CPU = 834.874 ms, elapsed = 833.564 ms.
============================
`pss': time = (0 s -> 21 ns)
============================
Important parameter values in tstab integration:
start = 0 s
outputstart = 0 s
stop = 21 ns
period = 1 ns
maxperiods = 20
step = 21 ps
maxstep = 40 ps
ic = all
useprevic = no
skipdc = no
reltol = 1e-03
abstol(V) = 1 uV
abstol(I) = 1 pA
temp = 27 C
tnom = 27 C
tempeffects = all
method = gear2
lteratio = 3.5
relref = sigglobal
cmin = 0 F
gmin = 1 pS
pss: time = 525 ps (2.5 %), step = 483.5 fs (2.3 m%)
pss: time = 1.287 ns (6.13 %), step = 863.3 fs (4.11 m%)
pss: time = 1.578 ns (7.51 %), step = 2.744 ps (13.1 m%)
pss: time = 2.44 ns (11.6 %), step = 1.996 ps (9.5 m%)
pss: time = 2.625 ns (12.5 %), step = 1.971 ps (9.39 m%)
pss: time = 3.492 ns (16.6 %), step = 2.259 ps (10.8 m%)
pss: time = 3.676 ns (17.5 %), step = 1.363 ps (6.49 m%)
pss: time = 4.543 ns (21.6 %), step = 1.086 ps (5.17 m%)
pss: time = 4.726 ns (22.5 %), step = 2.499 ps (11.9 m%)
pss: time = 5.598 ns (26.7 %), step = 2.286 ps (10.9 m%)
pss: time = 5.775 ns (27.5 %), step = 607.5 fs (2.89 m%)
pss: time = 6.638 ns (31.6 %), step = 999.4 fs (4.76 m%)
pss: time = 6.826 ns (32.5 %), step = 1.418 ps (6.75 m%)
pss: time = 7.632 ns (36.3 %), step = 630.2 fs (3 m%)
pss: time = 7.875 ns (37.5 %), step = 1.099 ps (5.23 m%)
pss: time = 8.646 ns (41.2 %), step = 471.5 fs (2.25 m%)
pss: time = 8.925 ns (42.5 %), step = 1.071 ps (5.1 m%)
pss: time = 9.742 ns (46.4 %), step = 2.252 ps (10.7 m%)
pss: time = 9.976 ns (47.5 %), step = 2.458 ps (11.7 m%)
pss: time = 10.86 ns (51.7 %), step = 2.665 ps (12.7 m%)
pss: time = 11.03 ns (52.5 %), step = 449 fs (2.14 m%)
pss: time = 11.91 ns (56.7 %), step = 733.5 fs (3.49 m%)
pss: time = 12.08 ns (57.5 %), step = 2.222 ps (10.6 m%)
pss: time = 12.99 ns (61.8 %), step = 1.774 ps (8.45 m%)
pss: time = 13.13 ns (62.5 %), step = 2.464 ps (11.7 m%)
pss: time = 14.01 ns (66.7 %), step = 631.9 fs (3.01 m%)
pss: time = 14.18 ns (67.5 %), step = 1.58 ps (7.53 m%)
pss: time = 15.06 ns (71.7 %), step = 1.931 ps (9.19 m%)
pss: time = 15.23 ns (72.5 %), step = 2.676 ps (12.7 m%)
pss: time = 16.12 ns (76.8 %), step = 1.729 ps (8.23 m%)
pss: time = 16.28 ns (77.5 %), step = 286.2 fs (1.36 m%)
pss: time = 17.15 ns (81.7 %), step = 868.3 fs (4.13 m%)
pss: time = 17.33 ns (82.5 %), step = 1.19 ps (5.67 m%)
pss: time = 18.19 ns (86.6 %), step = 2.236 ps (10.6 m%)
pss: time = 18.38 ns (87.5 %), step = 2.002 ps (9.53 m%)
pss: time = 19.18 ns (91.3 %), step = 2.22 ps (10.6 m%)
pss: time = 19.43 ns (92.5 %), step = 1.16 ps (5.53 m%)
pss: time = 20.26 ns (96.5 %), step = 656.6 fs (3.13 m%)
pss: time = 20.48 ns (97.5 %), step = 2.918 ps (13.9 m%)
Total time required for tstab analysis `pss': CPU = 249.32 s (4m 9.3s), elapsed = 250.305 s (4m 10.3s).
Time accumulated: CPU = 249.32 s (4m 9.3s), elapsed = 250.305 s (4m 10.3s).
Peak resident memory used = 111 Mbytes.
Conv norm = 12.8e+03, max dV(I0.I212|I0|T2_1__rcx:int_d) = 1.51496 V, took 247.78 s.
Important parameter values in pss iteration:
start = 20 ns
outputstart = 0 s
stop = 21 ns
period = 1 ns
maxperiods = 20
steadyratio = 10e-03
step = 21 ps
maxstep = 5 ps
ic = all
useprevic = no
skipdc = no
reltol = 100e-06
abstol(V) = 1 uV
abstol(I) = 1 pA
temp = 27 C
tnom = 27 C
tempeffects = all
errpreset = conservative
method = gear2
lteratio = 10
relref = alllocal
cmin = 0 F
gmin = 1 pS
==============================
`pss': time = (20 ns -> 21 ns)
==============================
pss: time = 20.03 ns (2.51 %), step = 91.17 fs (9.12 m%)
pss: time = 20.08 ns (7.5 %), step = 398.3 fs (39.8 m%)
pss: time = 20.13 ns (12.5 %), step = 111.1 fs (11.1 m%)
pss: time = 20.18 ns (17.5 %), step = 625.7 fs (62.6 m%)
pss: time = 20.23 ns (22.5 %), step = 422.5 fs (42.3 m%)
pss: time = 20.28 ns (27.5 %), step = 91.64 fs (9.16 m%)
pss: time = 20.33 ns (32.5 %), step = 678 fs (67.8 m%)