ATPG再了解(五)

Prepare for ATPG and Run ATPG

在吃進SPF後
執行
run atpg -auto

Always start with –auto. It provides the best starting point
and tradeoff between coverage and pattern count in the
current and future releases.

Auto Option:
This option runs ATPG in incremental mode, going from basic through sequential modes.
It automatically includes high pattern-compaction options, reducing test-program length.

下面是參考的scripts
set_messages -log lab1.log -replace

# Step 1: Reading libraries

read_net ../libs/libs_tmax.v.gz
read_net ../libs/rams.v
set_build -black_box PLL
set_build -black_box CLKMUL

# Step 2: Read design

read_netlist ../design_data/orca_final.v

# Step 3: Build ATPG Model

run_build_model

# Step 4: Perform Scan Design Rules Check

run_drc ../design_data/orca_final.spf

# Step 5: Prepare for ATPG

add_faults -all
set_atpg -capture 4

# Step 6: Run ATPG engine(s)

run_atpg -auto

整個指令細項
run_atpg
[-auto_compression]
[basic_scan_only | fast_sequential_only | full_sequential_only]
[-distributed]
[-ndetects ]
[-nodisturb_clock_grouping]
[-observe_file ]
[–only_chain_test]
[-random]
[-rerun_for_timing_exceptions]
[-resolve_differences]

以下是說明
How the Automatic Mode of Run ATPG Operates

The -auto_compression option of the run_atpg command can be helpful to assist with the optimal generation of compact sets of ATPG patterns. It is designed to automatically select the best settings and algorithms to provide reasonably good results. This page explains the sequence of steps used when run_atpg -auto_compression is selected.

Auto compression uses two algorithms: multiple fault sensitization and secondary test generation. Multiple fault sensitization, only enabled through -auto_compress, is a fast test generation algorithm that results in lower pattern count. Secondary fault test generation is good at detection, but slower than multiple fault sensitization.

Please Note that there is a restriction that the pattern source must be set to internal, the default.

1. User Pre-sets: Before beginning, you should use the set_atpg command to pre-select the ATPG abort limit, ATPG verbose mode, and possibly the ATPG merge effort. You may also wish to create a non-default fault population, or you can use defaults for any or all of these settings.

Once your ATPG setup is done, you initiate auto mode with the run_atpg -auto_compression command.
2. Fault List: If there is no existing fault population, then an add_faults -all is performed. If a fault population exists, it is left undisturbed and used for the remainder of steps.
必要時執行

3. Pattern Generation: A run_atpg pass is performed with pattern storage enabled and dynamic merge on. Merge effort is set to high, unless you have preset merge to some other value. The ATPG abort limit and capture cycle depth is whatever you have pre-selected. Verbose mode will also be whatever you have pre-selected. If capture cycles have been set to a number greater than 1, Fast-Sequential ATPG may be performed after Basic-Scan ATPG. Also, if -full_seq_atpg has been set on, Full-Sequential ATPG may be performed after Basic-Scan or Fast-Sequential.
4. Reports: After completion of ATPG, a report of fault summaries, test coverage, and pattern counts is produced. In addition, the total CPU time is reported.
5. Restoration: All settings are restored to their original values.

Note that multiple fault sensitization is only available if you use the -auto_compression option.