lagos.jl
Member level 1
Hi all! I am experiencing a very strange and rather frustrating problem while trying to run the same backannotated simulation in two different versions of Modelsim. In both cases I am using exactly the very same files for everything, and also the same compilation and simulation commands. The old version (Modelsim 5.8b) simulates fine and gives the expected results, while a newer release (Modelsim 6.2e) gives erroneous results. The following caption explains the situation:
h**p://obrazki.elektroda.pl/5_1169063659.jpg
****[Upper part of image: Modelsim 5.8b - Results: OK, as expected]
Notice pulse on signal "RNet7947' begining @ 10263ns and falling @ 10353ns. This is an update signal that is correctly fetched by the clock "RNet7665" @ 10353ns. The good, expected behavior is that the data in signal "WIR_shift" is updated to signal "PER/WIR", as shown.
****[Lower part of image: Modelsim 6.2b - Results: WRONG, unexpected]
Notice pulse on signal "RNet7947' this time begins @ 10264ns and falls @ 10354ns, too early to be fetched by the clock "RNet7665" (see carefully). Thus, the signal "WIR_shift" is NOT updated to signal "PER/WIR", which remains in "000", as shown.
I would be the most grateful if anybody could please give a clue to what is going wrong here. I REALLY need to get version 6.2e to run correctly with my design. The simulation command issued in both versions is as follows:
vsim -sdfmin /ram_16kx16_tap_top_tb_p1500/dfm_0=DFM_TC_Best.pt.sdf -sdfnoerror -sdfnowarn -t ns +mindelays work.ram_16kx16_tap_top_tb_p1500
In both cases I am using the same SDF file, with has the following header:
(DELAYFILE
(SDFVERSION "OVI 3.0")
(DESIGN "DFM_TC")
(DATE "Fri Nov 24 16:01:11 2006")
(VENDOR "COREM10LPHVT CORXM10LPHVT IOLIB_65_M10_CUP_FT_TEST_1V2 PRM10 splpll_16Kx8")
(PROGRAM "Synopsys PrimeTime")
(VERSION "V-2003.12-SP1-3")
(DIVIDER /)
// OPERATING CONDITION "Best::Best"
(VOLTAGE 1.32::1.32)
(PROCESS "0.8000::0.8000")
(TEMPERATURE -40.00::-40.00)
(TIMESCALE 1ns)
...
Thanks in advance!!!
Regards, JL.
h**p://obrazki.elektroda.pl/5_1169063659.jpg
****[Upper part of image: Modelsim 5.8b - Results: OK, as expected]
Notice pulse on signal "RNet7947' begining @ 10263ns and falling @ 10353ns. This is an update signal that is correctly fetched by the clock "RNet7665" @ 10353ns. The good, expected behavior is that the data in signal "WIR_shift" is updated to signal "PER/WIR", as shown.
****[Lower part of image: Modelsim 6.2b - Results: WRONG, unexpected]
Notice pulse on signal "RNet7947' this time begins @ 10264ns and falls @ 10354ns, too early to be fetched by the clock "RNet7665" (see carefully). Thus, the signal "WIR_shift" is NOT updated to signal "PER/WIR", which remains in "000", as shown.
I would be the most grateful if anybody could please give a clue to what is going wrong here. I REALLY need to get version 6.2e to run correctly with my design. The simulation command issued in both versions is as follows:
vsim -sdfmin /ram_16kx16_tap_top_tb_p1500/dfm_0=DFM_TC_Best.pt.sdf -sdfnoerror -sdfnowarn -t ns +mindelays work.ram_16kx16_tap_top_tb_p1500
In both cases I am using the same SDF file, with has the following header:
(DELAYFILE
(SDFVERSION "OVI 3.0")
(DESIGN "DFM_TC")
(DATE "Fri Nov 24 16:01:11 2006")
(VENDOR "COREM10LPHVT CORXM10LPHVT IOLIB_65_M10_CUP_FT_TEST_1V2 PRM10 splpll_16Kx8")
(PROGRAM "Synopsys PrimeTime")
(VERSION "V-2003.12-SP1-3")
(DIVIDER /)
// OPERATING CONDITION "Best::Best"
(VOLTAGE 1.32::1.32)
(PROCESS "0.8000::0.8000")
(TEMPERATURE -40.00::-40.00)
(TIMESCALE 1ns)
...
Thanks in advance!!!
Regards, JL.