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Altera_Forum's avatar
Altera_Forum
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18 years ago

derive_pll_clocks cmd and it's generated clk

Hi, I have a question regarding derive_pll_clocks. Quote taken from QII Handbook Vol 3 pg 6-36 Under title Derive PLL Clocks "If you use the write_sdc command after the derive_pll_clock ...
Altera_Forum's avatar
Altera_Forum
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18 years ago

write_sdc still works like it used to if you use "write_sdc -expand".

From the on-line help for write_sdc:

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Generates an SDC file with all current constraints and exceptions. When you use the -expand option, derive_clocks, derive_pll_clocks, derive_lvds_clocks and derive_clock_uncertainty macros are be expanded to corresponding sdc assignments before they are written to a file. If you do not use the -expand option, these macros are preserved.

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