Altera_Forum
Honored Contributor
14 years agoTimeQuest Constraint on PLL
I have a fairly trivial .sdc file which works with the following code:
# Constrain the external FPGA clock from oscillator create_clock -period 20 -name clk [get_ports CLK]# Derive pll clocks & clock uncertainty derive_pll_clocks derive_clock_uncertainty Now, I tried the following code and simply will not work. # -------------------------------------------------------# Constrain the Phase Locked Loop Master Clock = 50 MHz# ------------------------------------------------------- create_generated_clock -add -source Upll|altpll:altpll_component|PLL50_LOCK_altpll:auto_generated|pll1|inclk[0] -name Upll|altpll:altpll_component|PLL50_LOCK_altpll:auto_generated|pll1|clk[1] -master_clock clk [get_pins Upll|altpll:altpll_component|PLL50_LOCK_altpll:auto_generated|pll1|clk[1]] Now, in the above code (which is downsized font to make it fit on screen), I am referencing a PLL which I am instantiating with VHDL that was generated from the Mega Wizard. Upll: entity work.pll50_lock(syn) port map ( inclk0 => inclk0, c0 => clk1MHz, c1 => c1, locked => locked ); I have read Altera's documentation carefully . . . . and find the TimeQuest documentation to be vague on the naming conventions. The example given with a symbol rather than verilog or VHDL example is quite trying. I am wondering if anyone can see the problem with my code above to manually constrain the PLL clock. Thank you. James