Liberate_AMS for .lib generation.

Hi,

I'm using Liberate_AMS for characterising an AMS block....Even though my desired arc is getting characterised, the log file is getting filled with the error message attached below:

I'm attaching the screenshot of the same.

I'm not aware of what this feature 'Spectre_char_opt' is all about. Where am I inadvertently invoking it ? 

Guys, any help wud b great....

Liberate has this variable, spectre_use_char_opt_license, which is a common setting for all Liberate tools. By default it is "1", ie. "on". You can use set_var spectre_use_char_opt_license 0 to turn this off, if you do not have the required license for char_opt feature.

Hi,

I'm confused on the attributes setup_rising, hold_rising, setup_falling, hold_falling....apart from that I see rise_constraint, fall_constraint within each of those attributes. Whats the meaning of each of those attributes. Not getting a clear cut understanding from the user manual....

I'm having a clk signal with the active edge as the rising edge.

setup/hold_rise/falling are time_attribute value, which describes timing constraint between pin and related_pin when the signal at related_pin rises/falls (this depends on effective edge or level of clock). Depending on the data value, the output signal may rise or fall, hence the rise/fall_constraint section. All these are defined/explained in Liberty syntax manual. They are not Liberate-specific, therefore, not necessarily documented in Liberate manual.

Ok..So if I've understood correctly, if my active clk edge is rising edge, only setup_rising and hold_rising are valid attributes right ?........

yes.

Thanks Guangjun...

When using Liberate_AMS, In the Liberate_AMS RAK I came across guidelines on the observation_window values which needs to be given to capture the delay,setup/hold constraints. Is there such a guideline which need to be followed when capturing the mpw(min pulse width) .

In define_deck command, when i give 'types -timing' i get everything except mpw, I get mpw only when I specify 'types -mpw'.  Isn't mpw also supposed to come under 'timing' category as I have read so in the user manual. 

In the liberate_ams manual, it says, "Observation window is the clock period divided by 4" in one of the examples for define_deck. For further details, please read the manual.

Different sub-types of timing arcs are controlled by separate commands/variables in Liberate tools. mpw is not always required for all kinds of blocks. There may be special requirements in the settings that apply to mpw-type only. 

In case you do not know, we have local support teams around the world. You can submite Cases for various support requests. If you are interested in attending a training course, the local team can also help you on this.

Hi,

I'm trying to characterise a D flip flop using Liberate AMS. For the input stimulus, I'm creating tables (.tbl files) manually. I'm able to verify from the deck that my input stimulus is getting generated. I'm able to characterise the delay but I'm not able to characterise the setup & hold times. Given below a snapshot of the .tbl file and also a snapshot of the log...pls help

Please stop doing this. I already split the post you made yesterday (using the same information as above) in this thread into a separate post - here: Liberate for .lib generation of D flip flop

As I said there, the forum guidelines ask you not to continually post different issues in the same thread as it makes it very hard for anyone else to benefit from the existing threads if they are searching.

Andrew.

Sorry Andrew. I didnt know tht u had split the post into a seperate thread. On seing the post missing i thought it didnt get posted and so did the same thing again

please use liberate instead of liberate_ams.

please use liberate instead of liberate_ams.