how to deal eith the bist_clock for the mbist?

[davidyu]

Is the Dc support the output of the PLL as the mbist clock, if I want to combine the mbist with the JTAG, I
should setup the bist_clock(high speed) and bist_clock_lu(connect with JTAG TAP).


I have 2 problem.
1. can the PLL output clock act as the bist_clock?
2.why the bist_clock should be the integer of the bist_clock_lu, why?
3. which one case is good? connect the JTAG with mbist or add the input and output pads at the top level? why? and How many pads is dedicate only for the MBIST per mbist controller?
below is the information!!!!!!!!!!!!!!!!


The DW_mbist module has two clock inputs:
• One intended for low-speed operation, connected to TCK
• One intended for high-speed operation, connected to the memory clock
To configure the clocks, use the create_test_clock command to define the
memory clocks. Next, provide a high-speed definition of each memory clock,
and use a period that is an integer divisor of the test_default_period
value. Example 23 shows a high-speed clock definition where the period is
one-tenth of the test_default_period.
Example 23 Defining a High-Speed Clock
set_test_default_period 100
create_test_clock -w [list 45 55]
create_test_clock -w [list 4 5] -p 10 -mbist_clock

 

[bendrift]

hi, i use the rtl code for mbist not the DW.
can u tell me how to use the DW in dc for mbist?
thank u in advance.

 

[rlogin]

As my option,

question1: yes ( pll should be synchronized )

question2: cts can regard them as a clock group and adapt skew issue

question3: the first one is better (the second one is easy but expensive)

 

[davidyu]

Re: how to deal with the bist_clock for the mbist?

As I know, set_dft_config -mbist ;insert_dft and setup the test model, the DC can insert the mbist for us.

 

[zjwang]

you mean that DC can add the bist logic automatically using these commands?