DFTC的脚本命令

fl_5588 · 发表于 2012-1-15 21:21:49

本帖最后由 fl_5588 于 2012-1-15 21:26 编辑

我是采用unmapped方法，读入RTL来做DFT。clk与ret_n是RTL中的时钟与复位信号。
########
set_dft_signal -view existing_dft -type ScanClock
-port clk -timing {1 8.5}

set_dft_signal -view existing_dft -type Reset
-port rst_n -active_state 0

set_dft_signal -view spec -type ScanEnable
-port se
-active_state 1

create_test_protocol
######
1、如果这样写是对的话，为啥clk与rst_n用属性existing_dft ，而se用属性spec呢？DFTC的手册这样写的
Use the  set_dft_signal -view existing_dft command if the ports in your design are already connected and no connection is to be made by DFT Compiler.
Use the set_dft_signal -view spec command if the connections do not exist in your design and you expect DFT Compiler to make the connections for you.
没怎么看懂，第一次接触这些东西。
2、create_test_protocol -infer_clock \
            -infer_async                                  这个命令是DFTC手册给出的，但是网上有高人说不要这样，不知何原因。
3、能帮忙解释一下这两条命令吗
set test_default_strobe    90
set test_default_period    100

新手见笑了。谢谢大家的帮助。

lsqswl · 发表于 2012-1-15 21:21:50

1、set_dft_signal 后面还有个-type属性，clk与rst_n是rtl设计中已经存在并且定义的属性与-type属性一致，所以用existing_dft；se是使用 compile -scan 脚本把一般寄存器换成扫描寄存器的时候添加的新的接口，rtl中没有定义它是ScanEnable属性，新赋予它-type ScanEnable，所以用spec。
2、不晓得是哪个高手说的，希望给个链接！我也学习下。
3、设置缺省测试选通时间
设置缺省测试周期

我也是新手！我的理解如上，请楼主参考！

lsqswl · 发表于 2012-2-3 17:18:05

这是synopsys官网的一段问答！
Reusing '-view existing_dft' as '-view spec' for set_dft_signal
Question:

In DFT Compiler, I have defined the scan_in and scan_out ports by using the
'set_dft_signal -view existing_dft' command.

Why are these ports being used for insert_dft?
Answer:

This is done to make the scan reordering flow in Physical Compiler simpler.
Now, you do not need to use the following commands to redefine the same
scan_in and scan_out ports :
'set_dft_signal -view existing_dft' (for DRC purposes)
'set_dft_signal -view spec' (for inserting scan structures)

For the scan reordering flow in Physical Compiler, you read in a scan stitched
netlist.You use the descriptive view i.e the '-view existing' option to
declare all the existing DFT signals and also to define a scan path.
This is followed by the 'create_test_protocol' and 'dft_drc' commands to extract
the scan chain information.
You can run the 'report_scan_path' command to verify the scan chains.

The reordering then takes place based on placement. You run insert_dft (-physical)
which automatically reuses the extracted scan chain information
(i.e. reusing "existing_dft" as "spec").
Hence, you do not have to re-specify the scan_in and scan_out ports with
the '-view spec'option.

A sample script for the extraction would be:
# Read in the netlist
read_verilog SRC/RISC_CORE.v
link
current_design RISC_CORE

# Define the scan chains
set_scan_configuration -style multiplexed_flip_flop
set_dft_signal -view existing_dft -type ScanDataIn -port TEST_SI
set_dft_signal -view existing_dft -type ScanDataOut -port TEST_SO
set_dft_signal -view existing_dft -type ScanEnable -port TEST_SE
set_scan_path chain1 -view existing_dft -scan_data_in TEST_SI -scan_data_out TEST_SO

# Define the test signals
set_dft_signal -view existing_dft -type ScanClock -port CLK -timing [list 45 55]
set_dft_signal -view existing_dft -type Reset -port RESETN -active_state 0

# Extract scan chains
create_test_protocol
dft_drc
report_scan_path -view existing_dft -chain all
report_scan_path -view existing_dft -cell all

For the reordering in Physical Compiler, in addition to the above you would
require the following commands:
preview_dft -physical
insert_dft -physical
dft_drc

lsqswl · 发表于 2012-2-3 17:20:28

这是synopsys官网的一段问答，楼主自己参考！ existing_dft&view spec.doc (24.5 KB, 下载次数: 176 )

2012-2-3 17:20 上传
点击文件名下载附件

fl_5588 · 发表于 2012-2-6 09:57:55

回复 4# lsqswl

谢谢楼上回答。
1、什么是选通时间？测试周期呢？
2、这段话出自用户手册。

DFT Compiler Scan User Guide.pdf (6.08 MB, 下载次数: 646 )
3、现在我理解existing_dft就是已经在RTL中有连线的信号，而spec是空端口，用来留给插入链使用的。
THX

lsqswl · 发表于 2012-2-6 13:06:33

两种strobe协议：一种是strobe_after_clock，一种是strobe_before_clock。默认是strobe_after_clock的。
test_default_strobe:定义探测点的位置
test_default_period：定义测试周期，如果测试仪和被测芯片允许，可以设更小的值，默认是100ns

这两个值都没有改过，一般都采用默认，貌似跟ATE有关系！就这些信息了，我也不知道具体怎么理解它，楼主怎么理解的可以讨论一下。