DFT compiler commands

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chis4yu

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Hi,

I'm a little confused by DFT compiler and usage.

I understand that the normal clock is defined as the ScanClock with existing_dft

but I'm adding a bypass MUX in RTL.

Seems like the clock used for scan chain insertion ALWAYS uses functional clk name. In this case : clk.

Seems like the assumption is that "clk" will ALWAYS be the scan and capture clock.

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module ABC (clk, rst, d, q)
  always @(posedge clk or posedge rst)
     if (rst)
          q <= '0;
     else
          q <= d;
endmodule
 
module XYZ (clk, scanclk, rst, scanrst, d, q, TestMode)
 
assign clk_bypass = TestMode ? scanclk : clk;  // if TestMode then use scanclk else use functional clock
 
ABC i_ABC (.clk(clk_bypass),
                .rst(rst_bypass),
                .d(d),
                .q(q)
);
endmodule

what's the correct DFT compiler commands to add scan to module XYZ ?

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set_dft_signal -view existing_dft -ScanClock -port clk 
set_dft_signal -view existing_dft -ScanReset -port rst
set_dft_signal -view existing_dft -type Constant -active 1 -port TestMode

How to handle and describe scanrst, scanclk to properly insert scan chain and connect to scanrst, scanclk ?

What's the correct syntax for the "set_dft_signal -view spec" to create the scan chains for "insert_dft"

Code dot - [expand]
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set_dft_signal -view spec -ScanClock -port clk
set_dft_signal -view spec -ScanReset -port rst
set_dft_signal -view spec -type Constant -active 1 -port TestMode


Thanks
 
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