Mentor v8.6_4 - page 710

FastScan and FlexTest Reference Manual, V8.6_4

4-6

FastScan Test Pattern File Format Test Pattern File Formats

CHAIN_TEST =

APPLY “test_setup” <value> <time>;

PATTERN = <number>;

APPLY “scan_group_load_name” <time> =

CHAIN “scan_chain_name1” = “values....”;

CHAIN “scan_chain_name2” = “values....”;

....

END;

APPLY “scan_group_unload_name” <time> =

CHAIN “scan_chain_name1” = “values....”;

CHAIN “scan_chain_name2” = “values....”;

....

END;

The optional “test_setup” line is applied at the beginning of the functional chain

test pattern if there is a test_setup procedure in the Setup_Data section. The

number for the pattern is a zero-based pattern number where a functional scan

chain test for all scan chains in the circuit is to be tested. The scan group load and

unload name and the scan chain name will be enclosed in double quotes. The

values to load and unload the scan chain will be enclosed in double quotes.

During the loading of the scan chains, each value of the corresponding scan chain

will be placed at its scan chain input pin. The shift procedure will shift the value

through the scan chain and continue shifting the next value until all values for all

the scan chains have been loaded. Since the number of shifts is determined by the

length of the longest scan chain, X’s (don’t care) are placed at the beginning of the

shorter scan chains. This will ensure that all the values of the scan chains will be

loaded properly.

During the unloading of the scan chains, each value of the corresponding scan

chain will be measured at its scan chain output pin. The shift procedure will shift

the value out of the scan chain and continue shifting the next value until all values

for all the scan chains have been unloaded. Again, since the number of shifts is

determined by the length of the longest scan chain, X’s (don’t measure) are placed

at the end of the shorter scan chains. This will ensure that all the values of the scan

chains will be unloaded properly.