IC614 netlist and openaccess

The verilog.ams netlist is produced by the cell-based AMS netlister, and can be enabled (via Tools->AMS->Options in the CIW) to netlist at check-and-save time. It can also be produced when using other tools in the AMS flow. It is a netlist of the design in that specific schematic. The "sch.oa" file is the OpenAccess database storing the schematic - the physical information and connectivity in the schematic.

I don't know what "a tool of database gestion" means.

Andrew.

Sorry for "tool of database gestion" :). I meant a database administrator tools, a tool other than the schematic editor that edit the sch.oa. Because, after parasitic extraction for example, the schematic editor is very difficult to work with, because of the high number of components.

Thanks Andrew

You could use SKILL functions to edit the database?

Andrew.

 SKILL function is a scripting language, isn't it ? It will not allow me to see the sch.oa as a list of component interconnected and modify one of them if I need. 

 Yes (it's actually a full featured programming language). It will allow you to access all the components, how they are interconnected, and change one if you need. Of course, you have to have some knowledge of the language, but there is lots of documentation on SKILL and many examples on Cadence Online Support - http://support.cadence.com

And many examples in this forum (this forum is the Cadence IC SKILL forum after all)

Regards,

Andrew.

 Hi Andrew,

Could you explain me how to change the resistance value of all the resistors (analogLib) of a schematic to a unique value x please ? I have to use Skill Development Environment to make this ?

Regards

Hi

I progressed in my skill study.

I used the following procedure that I encountered on the web and tried to modify it to change all "p_res" in my schematic to 1e-6 ohm :

procedure(cb(lib cell)
;let will allow you to access the cv and newlabel variables outside
;of this procedure
let((cv newLabel)
;open the cellview as a database object and assign it to cv
cv = dbOpenCellViewByType(lib cell "schematic" "" "a")
;for loop to go through all instances in this cellview
foreach(instance cv~>instances
;open the property window -- this will display the window!
geSelectObjectNoFilter(instance)
;check the cellname and change the bulk node (bn) property
if(schObjPropForm->cellName->value == "p_res"
then
schObjPropForm->r->value = "1e-6"
)
;close the form
hiFormDone(schObjPropForm)
geDeselectAll()
);end foreach
);end of let
);end procedure

 But I obtain the error :

 ...

db:0x160809cf db:0x160809cd db:0x160809cc db:0x160809cb db:0x160809c8

db:0x160809c7 db:0x160809c5 db:0x160809c4 db:0x160809c2 db:0x160809c1

db:0x160809bf db:0x160809be db:0x160809bc db:0x160809ba db:0x160809b8

db:0x160809b7 db:0x160809b5 db:0x160809b4 db:0x160809b2 db:0x160809b1

...

)

What does it mean please ? What is the problem ?

Thanks

That's not an error, it's simply the return value of the foreach - which will return the list of database objects passed in. 

That said, doing it via having the edit properties form open is not exactly very clean.

Simpler would be to do:

foreach(instance cv~>instances
  when(instance~>cellName=="p_res"
    instance~>r="1e-6"  ; I assume you do not really want to set it to 1uOhm (that's not good for the simulator to have it so low)
  )
)

This gets rather more complicated if the component has CDF Callbacks which need to be triggered to compute derived parameters - for that you would want to use How to call CDF Callbacks procedurally from SKILL?

Regards,

Andrew.

OK, thank you very much Andrew

Your method is really faster to do the work. For resistor value, I want to short-circuit all of them. So I use this very little value. But, it is true that it might cause numeric problems. Any suggestion ?

Regards,

Set the value to 0 rather than 1u. 0 ohm resistors are OK (in spectre at least).

Andrew.