Hello Altera,
I am basically a Altera competitor user and moved quite recently to Altera Time Quest.
In my Altera design, i need to apply some Multicycle Path exceptions for both -setup and -hold relationship.
Latest competitor tools purely follow Synopsys sdc standard for MCP constraints;
i.e. As per Synopsys sdc specification; the integer value for the -hold argument specifies the number of clock cycles to move the capture edge backward with respect to the default position (relative to the valid setup relationship); the default setting is 0.
For e.g.:
set_multicycle_path -setup 5 -from [get_cells FF1] -to [get_cells FF2]
set_multicycle_path -hold 4 -from [get_cells FF1] -to [get_cells FF2]
To move the capture edge for the hold relationship back to time=0, you need to use set_multicycle_path -hold 4 to move the capture edge back by four clock cycles .
To summarize, Synopsys determines the number of hold cycles as follows:
(hold cycles) = (setup option value) – 1 – (hold option value)
Can you please help me understand if this rule also applies to TimeQuest. ?
Regards,
freak
