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How to route output clock of alt2gxb to a pll?

Altera_Forum
Honored Contributor II
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Hi, 

The error information is 

"Error: Clock input port inclk[0] of PLL "pllo:u_pllo|altpll:altpll_component|pll" 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 "pllo:u_pllo|altpll:altpll_component|pll" is driven by siigx125_phyx1:phy|altpcie_serdes_2sgx_1x125:phypcsx1|alt2gxb:alt2gxb_component|rx_coreclk_in[0] which is CLKOUT output port of HSSI_TRANS type node" 

 

I'd like to create additional x1 and x(1/2) in-phase clock based on alt2gxb:clk. 

Thus, alt2gxb:clk is connected to a altpll module. 

But it caused above error. 

 

Please help. 

 

Jimmy
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Altera_Forum
Honored Contributor II
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Hello, 

 

The siigx handbook says, in the volume-2 page 7-73, "An internally generated global signal cannot drive the PLL". The clock output from the alt2gxb is always routed through global signal, so you can't do this.
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Altera_Forum
Honored Contributor II
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Thanks for reply. 

Its my first time to run altera fpga. 

do you have any suggestions about my requirement? 

 

best regards, 

Jimmy 

note, I try to output gxb clock outside fpga chip and connect it back to a clock pin , then  

atlpll can generate x1 and x(1/2) in-phase clock. But timing between gxb:clk and pll:x1/x(1/2) clock cannot be check exactly.
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Altera_Forum
Honored Contributor II
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Hi, 

 

I don't know if it meets your requirement, but the only way I can figure out is to use phase comp fifo in the gxb like handbook vol-2 page 2-131. I attached the sample. 

 

Thanks!
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