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Altera_Forum's avatar
Altera_Forum
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16 years ago

Set constraint for timequest

hi. i just start to use timequest. some simple question wondering me and needs confirmation. 1. If use the clock enable method as frequency divider, is necessary to set constraint? 2. ...
Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
16 years ago

rbugalho (http://www.alteraforum.com/forum/member.php?u=27812),

i have look at the example, and some constraints confuses me. Can you clear my doubt on the question below?

constraints:

1. create_generated_clock -name clk_div_2 -source [get_ports {fast_clk}] -divide_by 2 [get_pins {enable_reg|q}]

2. set_multicycle_path 2 -to [get_fanouts [get_pins -hier enable_reg|q*] -through [get_pins -hier *|*ena*]] -setup

Question:

1. Why they don use -hier before {enable_reg|q} in 1st constraint and use it in 2nd constraint?

2. In the second constraint,the syntax through is exception?

Besides, how to apply constraint for certain module only?

thanks