Fastscan
Combinational ATPG
Updated by Ashvitha Kamatala and Samiha Mourad
on Feb. 2, 2001
-
Fastscan is a program that generate test patterns for combinational circuits
and circuit with scan features
-
Make a subdirectory for your design and write the verilog hdl code in this
directory
-
Fastscan requires a test library. The test library identifies the functions
of each part in the design. A test library is given at the end of this
page. Cut and paste the test library into a text editor and save it as
atglib
in
the directory you plan to run your project from.
-
Set the mentor graphics working directory to the directory which you plan
to execute fastscan from. Make sure you are in this directory when you
execute the following shell command:
shell> MGC_PWD=`pwd`
-
To invoke Fastscan as a command line interface add the -nogui option as
shown the second line
shell > fastscan <design_name>.v -verilog -lib atglib
The following windows will appear
shell > fastscan <design_name>.v -verilog -lib atglib
-nogui
-
Set the system mode for automatic test pattern generation. This command
will also do rule checking to make sure that the scan circuitry you have
identified will function correctly.
SETUP> set system mode atpg
-
If you wish to do IDDQ testing, enter the following command, otherwise
skip this step:
ATPG> set fault type IDDQ
-
Add all the stuck at faults in the circuit. Enter the following command:
ATPG> add faults -all
-
Generate the test vectors by entering the following command:
ATPG> run
-
Check to see how much fault coverage that you received from the patterns.
In addition this command will show you how many test vectors were generated.
ATPG> report statistics
For an explanation of the fault types in report statistics, click here.
-
Next check and see which of the faults are untestable. Enter the following
command.
ATPG> report faults -Class UT -all
-
Save the patterns in an ASCII file format by entering the following command:
ATPG> save patterns mux.pats
Then you can print the file to inspect the patterns
-
To terminate the session, at the popup command line, select:
exit
or, from the command line, enter:
ATPG> exit
click
here to go back to the Index
Test Library
model anotb (OUT, B, A) (
input(B) ()
input(A) ()
intern(_NN0) (function = !A;)
output(OUT) (function = B * _NN0 ;)
)
model aorbn (OUT, B, A) (
input(B) ()
input(A) ()
intern(_NN0) (function = !A;)
intern(_NN4) (function = B * _NN0 ;)
output(OUT) (function = !_NN4;)
)
model dff (QBAR, Q, DATA, CLOCK) (
input(DATA) ()
input(CLOCK) ()
intern(_NN0) (function = !CLOCK;)
output(Q) (primitive=_dff(,,_NN0,DATA,Q,);)
output(QBAR) (function = !Q;)
)
model dfsc (SCAN, QBAR, Q, DATA1, DATA, CLOCK) (
scan_definition(
type = mux_scan;
scan_out = Q;
scan_in = DATA1 ;
scan_enable = SCAN;
non_scan_model = dff(QBAR, Q, DATA, CLOCK);)
input(SCAN) ()
input(DATA1) ()
input(DATA) ()
input(CLOCK) ()
intern(_NN7) (primitive=_mux(DATA,DATA1,SCAN,_NN7);)
intern(_NN0)
(function = !CLOCK;)
output(Q) (primitive=_dff(,,_NN0,_NN7,Q,);)
output(QBAR) (function = !Q;)
)
model dffr (RESET, QBAR, Q, DATA, CLOCK) (
input(RESET) ()
input(DATA) ()
input(CLOCK) ()
intern(_NN1) (function = !CLOCK;)
intern(_NN0) (function = !RESET;)
output(Q) (primitive=_dff(,_NN0,_NN1,DATA,Q,);)
output(QBAR) (function = !Q;)
)
model dfscr (SCAN, RESET, QBAR, Q, DATA1, DATA, CLOCK) (
scan_definition(
type = mux_scan;
scan_out = Q;
scan_in = DATA1 ;
scan_enable = SCAN
non_scan_model = dffr(RESET, QBAR, Q, DATA, CLOCK);)
input(SCAN) ()
input(RESET) ()
input(DATA1) ()
input(DATA) ()
input(CLOCK) ()
intern(_NN9) (primitive=_mux(DATA,DATA1,SCAN,_NN9);)
intern(_NN1) (function = !CLOCK;)
intern(_NN0) (function = !RESET;)
output(Q) (primitive=_dff(,_NN0,_NN1,_NN9,Q,);)
output(QBAR) (function = !Q;)
)
model dffsr (SET, RESET, QBAR, Q, DATA, CLOCK) (
input(SET) ()
input(RESET) ()
input(DATA) ()
input(CLOCK) ()
intern(_NN2) (function = !CLOCK;)
intern(_NN1) (function = !RESET;)
intern(_NN0) (function = !SET;)
output(Q) (primitive=_dff(_NN0,_NN1,_NN2,DATA,Q,);)
output(QBAR) (function = !Q;)
)
model dfscsr (SET, SCAN, RESET, QBAR, Q, DATA1, DATA0, CLOCK) (
input(SET) ()
input(SCAN) ()
input(RESET) ()
input(DATA1) ()
input(DATA0) ()
input(CLOCK) ()
intern(_NN11) (primitive=_mux(DATA0,DATA1,SCAN,_NN11);)
intern(_NN2) (function = !CLOCK;)
intern(_NN1) (function = !RESET;)
intern(_NN0) (function = !SET;)
output(Q) (primitive=_dff(_NN0,_NN1,_NN2,_NN11,Q,);)
output(QBAR) (function = !Q;)
)
model inv1 (OUT, IN1) (
model nd2x1 (OUT, IN2, IN1) (
input(IN2) ()
input(IN1) ()
intern(_NN3) (function = IN1 * IN2 ;)
output(OUT) (function = !_NN3;)
)
model nd4 (OUT, IN4, IN3, IN2, IN1) (
input(IN4) ()
input(IN3) ()
input(IN2) ()
input(IN1) ()
intern(_NN5) (function = IN1 * IN2 * IN3 * IN4 ;)
output(OUT) (function = !_NN5;)
)
model ndi2x1 (OUT2, OUT1, IN2, IN1) (
input(IN2) ()
input(IN1) ()
output(OUT2) (function = IN1 * IN2 ;)
output(OUT1) (function = !OUT2;)
)
model nr3 (OUT, IN3, IN2, IN1) (
input(IN3) ()
input(IN2) ()
input(IN1) ()
intern(_NN0) (function = IN1 + IN2 + IN3 ;)
output(OUT) (function = !_NN0;)
)
model xor (OUT, IN2, IN1) (
input(IN2) ()
input(IN1) ()
output(OUT) (primitive=_xor(IN1,IN2,OUT);)
)