Subthreshold Standard Cells Characterization by Liberate

Hi there,

I'm trying to characterize a standard cells library. I'm using tcl-files, based on RAK.

Nwell of cells in this library does not connected to VDD but also to VDDNW, which could have other values, e.g. 0 V. I set the voltages in char_setup file in this way:

set_vdd     -attributes {related_bias_pin VDDNW direction input voltage_name VDD}  VDD  ${VDD}

set_vdd     -type nwell -attributes {pysical_connection device_layer direction input voltage_name VDDNW }  VDDNW  0

set_gnd VSS 0

Please notice, that there is not any pin with the name VDDNW in the cells layout. For LVS of cells I added tapcell, comprising VDD, VDDNW and VSS, to the cell layout.

Characterization starts and aborts very fast without generating any desired results (see below message on the screen).

---------------------------------------------------------------

Starting on grid with 10 cpus
---- Template Generation start ----
---- Template Generation done ----
-- Characterization Summary --
0 warnings
0 errors

Starting on grid with 10 cpus
---- Characterization start ----
---- Characterization done ----
-- Characterization Summary --
0 warnings
0 errors

Starting on grid with 2 cpus
---- Write library start ----
---- Write library done ----
-- Write library Summary --
0 warnings
0 errors
0 monotonicity warnings

Starting on grid with 2 cpus
---- Write CCS library start ----
[5]    Done

--------------------------

The tool messages in the log file just after initialization step:

can't read "VDDNW": no such variable while executing

Question:

1.  For postlayout simulation I generated for each cells (inclusive tapcell) parasitics. Should I do extraction for each cell manually again or Liberate does this job?

   - in cell_list there are only the name of cells (not tapcell)

2. could be the missing of tapcell the reason of characterization abort?

I appreciate any suggestion of you.

Thanks a lot in advance!

BarPouy