[help] how to set_dont_use in soc encounter?

[iamczx]

set_dont_use

when insert buffer to fix timing. I want to use buf4, not buf16 and so on... But how to tell the soc encounter dont use those cells ?
thanks

 

[jelydonut]

set_dont_use cadence

I could be wrong.. but im pretty sure the buffers you list in the .ctstch file define which buffers are used for clock tree synthesis..

AutoCTSRootPin clk_pad/Y
NoGating rising
MaxDelay 3ns
MinDelay 0ns
MaxSkew 30ps
SinkMaxTran 400ps
BufMaxTran 400ps
Buffer BUX1 BUX2 BUX3 BUX4 BUX8 BUX12 BUX16 BUX20 INX1 INX2 INX3 INX4 INX8 INX12 INX16 INX20

either that or i misunderstood the question..

jelydonut

 

[lcf0451]

encounter sinkmaxtran

What is soc encounter used for?

 

[joe2moon]

write_sdc soc encounter

>> ...insert buffer to fix timing.

Just write a SDC file, such as set_dont_use_cells.sdc, then use
"loadTimingCon"command to load the constraint.

encounter> loadTimingCon -incr set_dont_use_cells.sdc

Example of "set_dont_use_cells.sdc"

set_dont_use your_lib/buf16
set_dont_use your_lib/buf20
:
:
-----------------------------------------------------------------------------------------

>> What is soc encounter used for?

SoC Encounter?, a configuration of the Cadence® Encounter® digital IC design platform, supports this capability by combining RTL synthesis, silicon virtual prototyping, and full-chip implementation into a single system.

For more detail, please refer to the following link
https://www.cadence.com/products/digital_ic/soc_encounter/index.aspx

 

[sam31]

encounter autoctsrootpin

Hi,

Why you don't want to use buf8 ,buf12 and so on ?

 

[iamczx]

soc encounter for designers

>> ...insert buffer to fix timing.

Just write a SDC file, such as set_dont_use_cells.sdc, then use
"loadTimingCon"command to load the constraint.

encounter> loadTimingCon -incr set_dont_use_cells.sdc

Example of "set_dont_use_cells.sdc"

set_dont_use your_lib/buf16
set_dont_use your_lib/buf20
:
:
-----------------------------------------------------------------------------------------

hello joe2moon, the soc encounter doesn't recongnize the set_dont_use command.
and the set_dont_use command will not exist in the sdc file when you use write_sdc command in the design_compiler.

Added after 6 minutes:

sorry joe2moon, your method is ok.
Maybe I have done something wrong when I try the command last time.

Added after 2 minutes:

Hi,

Why you don't want to use buf8 ,buf12 and so on ?

The designers don't want to use those buffer..

Added after 15 minutes:

hi jelydonut,thanks you too.
Although I am not under the situation of buffers are clock tree synthesis.

 

[Kulprashant]

index of soc encounter

Hi,
u check when u inserting buffers, it will ask which r the buffers to be added then accoding to ur usage u can select the name of the buffer.


Prashant