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ALTPLL synthesis issue

Altera_Forum
Honored Contributor II
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I am trying to use ALTPLL megafunction in my design. I generated the IP using the megafunction IP manager. then i've instantated that in my top-level design and hooked it up in the following manner. 

 

module designTop ( 

inclk0, PLL_RESET, PLL_LOCKED, SYSCLK, CR4CLK ); 

input inclk0, PLL_RESET; 

output PLL_LOCKED, SYSCLK, CR4CLK; 

 

pcst_sysclkpll pcst_sysclkpll_inst ( 

.areset ( PLL_RESET ), 

.inclk0 ( inclk0 ), 

.c0 ( SYSCLK ), 

.c1 ( CR4CLK ), 

.locked ( PLL_LOCKED ) 

);  

endmodule 

 

I get the following error: 

 

Info: Input port INCLK[0] of node "pcst_sysclkpll:pcst_sysclkpll_inst|altpll:altpll_component|pcst_sysclkpll_altpll:auto_generated|pll1" is driven by inclk0~buf0 which is COMBOUT output port of LOGIC_CELL_COMB type node inclk0~buf0 

 

Error: Clock input port inclk[0] of PLL "pcst_sysclkpll:pcst_sysclkpll_inst|altpll:altpll_component|pcst_sysclkpll_altpll:auto_generated|pll1" must be driven by a non-inverted input pin or another PLL, optionally through a Clock Control block 

 

Even though i've connected the inclk0 to a top-level input pin, Quartus is placing a buffer before the inclk0 pin of the PLL resulting the above error. how do i resolve this? 

Thanks
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Altera_Forum
Honored Contributor II
890 Views

What device are you using and which pin is inclk0 assigned to?

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Altera_Forum
Honored Contributor II
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Iam using startixIII EP3SL340F1517C3. i've assigned it to pin_AA1 which is a dedicated CLK pin (CLK8n) and IOBank_5C. 

Thanks.
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Altera_Forum
Honored Contributor II
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Hi, 

I have just replicated your design and PLL including pin placement and do not have the error that you observed. 

 

What version of Quartus are you running? 

 

Rgds 

V
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Altera_Forum
Honored Contributor II
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i am using vesion 8.0 SP1, build 07/10/2008 SJ Full version. 

 

I have tried the following things in my end and still have the issue: 

A. Assigning pin location thru synthesis directive instead of thru pin planner: 

input inclk0 /* synthesis chip_pin = "AA1" */; // input Clock 

I got the same error. 

 

B. Driving the PLL input thru altclkctrl in the following manner: 

altclkctra pcst_altclkctrl_inst1 ( 

.inclk (inclk0), 

.outclk (pll_clkin) );  

pcst_sysclkpll pcst_sysclkpll_inst ( 

.areset ( PLL_RESET ), 

.inclk0 ( pll_clkin ), 

.c0 ( SYSCLK ), 

.c1 ( CR4CLK ), 

.locked ( PLL_LOCKED ) 

);  

 

I got the following error: 

Error: Clock input port inclk[0] of PLL "pcst_sysclkpll:pcst_sysclkpll_inst|altpll:altpll_component|pcst_sysclkpll_altpll:auto_generated|pll1" must be driven by a non-inverted input pin or another PLL, optionally through a Clock Control block 

Info: Input port INCLK[0] of node "pcst_sysclkpll:pcst_sysclkpll_inst|altpll:altpll_component|pcst_sysclkpll_altpll:auto_generated|pll1" is driven by altclkctra:pcst_altclkctrl_inst1|altclkctra_altclkctrl_nie:altclkctra_altclkctrl_nie_component|wire_clkctrl1_outclk which is OUTCLK output port of CLKCTRL type node altclkctra:pcst_altclkctrl_inst1|altclkctra_altclkctrl_nie:altclkctra_altclkctrl_nie_component|clkctrl1 

 

eventhough it is driven by CLKCTRL node, i get the same error and dont understand why.
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Altera_Forum
Honored Contributor II
890 Views

 

--- Quote Start ---  

i am using vesion 8.0 SP1, build 07/10/2008 SJ Full version. 

 

I have tried the following things in my end and still have the issue: 

A. Assigning pin location thru synthesis directive instead of thru pin planner: 

input inclk0 /* synthesis chip_pin = "AA1" */; // input Clock 

I got the same error. 

 

B. Driving the PLL input thru altclkctrl in the following manner: 

altclkctra pcst_altclkctrl_inst1 ( 

.inclk (inclk0), 

.outclk (pll_clkin) );  

pcst_sysclkpll pcst_sysclkpll_inst ( 

.areset ( PLL_RESET ), 

.inclk0 ( pll_clkin ), 

.c0 ( SYSCLK ), 

.c1 ( CR4CLK ), 

.locked ( PLL_LOCKED ) 

);  

 

I got the following error: 

Error: Clock input port inclk[0] of PLL "pcst_sysclkpll:pcst_sysclkpll_inst|altpll:altpll_component|pcst_sysclkpll_altpll:auto_generated|pll1" must be driven by a non-inverted input pin or another PLL, optionally through a Clock Control block 

Info: Input port INCLK[0] of node "pcst_sysclkpll:pcst_sysclkpll_inst|altpll:altpll_component|pcst_sysclkpll_altpll:auto_generated|pll1" is driven by altclkctra:pcst_altclkctrl_inst1|altclkctra_altclkctrl_nie:altclkctra_altclkctrl_nie_component|wire_clkctrl1_outclk which is OUTCLK output port of CLKCTRL type node altclkctra:pcst_altclkctrl_inst1|altclkctra_altclkctrl_nie:altclkctra_altclkctrl_nie_component|clkctrl1 

 

eventhough it is driven by CLKCTRL node, i get the same error and dont understand why. 

--- Quote End ---  

 

 

Hi, 

 

I run your code with Quartus II 8.0 SP1 (Full Version) ,including the pin assignment for the input clock, and it works fine. Did also constrain the other pins ?
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Altera_Forum
Honored Contributor II
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After i deleted all my pin assignments and ran, i didn't get the error. didn't understand why my assignments was causing the above error. But now it is resolved. Thanks everyone for the timely tips.

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