Altpll using output frequency

[Altera_Forum]

Dear, 

 When compiling a simple project with the attached pll as a toplevel i get the following error because i try to use output frequence parameter in stead of device and multiply parameters. Q9.1--> Error: PLL "altpll:altpll_component|altpll_ign2:auto_generated|pll1" has port CLK[0] connected but parameters clk0_multiply_by and/or clk0_divide_by are either unspecified or set to 0  I really want to define the output frequency in stead of devision and multiply factors.  Can somebody make this work?  Thx,  Johannes  more info:  I want to create a pll based on a vhdl file not using the gui because I want to do batch compilation of pll's with different output frequency settings.  This is what i did: I started from a megawizard generated file. The project compiles fine. I looked in the autamtically generated file and saw that a clock devision and multiplier parameter was created (although is specified a frequency in the megawizard): "  clk0_divide_by : NATURAL;  clk0_multiply_by : NATURAL; "  I'd like to work with the output frequency parameter instead as stated in the "The Phase-Locked Loop (ALTPLL) Megafunction User Guide"   "CLK[]_OUTPUT_FREQUENCY: Integer:  Specifies the output frequency of the corresponding output clock port, CLK[9..0].This parameter is ignored if the corresponding CLK[9..0] port is not used. This parameter is unavailable if multiplication or division factors are specified. If omitted, the default is 0."  When compiling a simple project with the attached pll as a toplevel i get the following error: --> Error: PLL "altpll:altpll_component|altpll_ign2:auto_generated|pll1" has port CLK[0] connected but parameters clk0_multiply_by and/or clk0_divide_by are either unspecified or set to 0  I guess it has something to do with the statement in the user guide at the devide/multiply paramerters: "Specifies the integer division factor for the VCO frequency of the corresponding output clock port, CLK[9..0] port. The parameter value must be greater than 0. Specify this parameter only if the corresponding CLK[9..0] port is used; however, it is not required if a clock settings assignment is specified for the corresponding clk[9..0] port. If omitted, the default is 0."  What Clock Settings assignment????  Kind regards,  Johannes

[Altera_Forum]

You didn't clarify, if you manually edited the MegaFunction generic parameters or if the wizard generated file causes an errot in Quartus compilation?

[Altera_Forum]

The megawizard generated file compiles fine, but it uses the multiply and devide parameters in stead of the output frequency parameter. 

 When i try to adapt the generated file manually (as in the attached file) it goes wrong. I simply ommit the clk0_divide_by and the clk0_multiply_by parameters and replace it with the clk0_output_frequency parameter and it fails to compile.  Regards,  Johannes

[Altera_Forum]

Judging by your own work I can say: 

 The frequency parameter need to be converted to PLL parameters of mult/div and not the other way round. PLLs ar based on these figures for their internal counters. Frequency entry is just a user convenience.   You will need to convert frequency manually to mult/div factors if you don't want GUI. Remember not all frequencies are possible. Only those that fit the mult/divide values.

[Altera_Forum]

I agree, that according to the MegaFunction user manual the clkx_output_frequency parameter should work, but it seem to be unsupported. I wasn't aware of, because I'm using mutiplier/divider also in manual PLL instantiation.

[Altera_Forum]

Dear, 

 Thx for the effort, I think i worked it out.  You can use clkx_output_frequency parameter IF you define the multiply and devision factors in the SDC file. Make a clock and derived clock for the pll clocks.   It seems that one needs either way to supply Quartus with multiply and devision factors. So i have to agree with kaz and calculated myself the mult and div factors. This is not so easy as it seams because their are a lot of restricions eg. Fvco max/min, m max, n max, c max,.... And it is frustrating because i know Quartus CAN do it (it does it in the megawizard GUI!). Not very convenient for the user :-(  Anyhow: if their are more tips to tackle this problem in an elegant way just add them to this tread! I will be gratefull.  Have a nice old to new!  Johannes