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my PLL does not set "pll_locked" to 1 when I lower "pll_powerdown" to 0. The flag "PLL Auto Reset" is set in the IP core

Длаза
Novice
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9 Replies
a_x_h_75
New Contributor III
188 Views

"pll_powerdown"? What FPGA are you using? Do you mean the reset port - 'rst'?

 

What is your clock source? Is it a good clock source with low jitter? What frequency are you trying to lock to?

 

Cheers,

Alex

Длаза
Novice
188 Views

Arria 10GX. FPLL have input pin - "pll_powerdown". This is analog of reset

 

Длаза
Novice
188 Views

Input clock 50MHz, output clock -156.25MHz. Higher lickly jitter is high

 

a_x_h_75
New Contributor III
188 Views

What are you connecting pll_powerdown to? Are you using it with a Transceiver and is it connected to that? Is it connected to the correct reset controller?

 

The user guide states it "needs to be connected to a dynamically controlled signal". Don't expect it to work if you're driving it directly.

 

Cheers,

Alex

Длаза
Novice
188 Views

When I tested my project, then through the reset controller I changed the status pll_powerdown, but pll_locked did not change its state. Null.

 

a_x_h_75
New Contributor III
188 Views

Are you simulating this? pll_powerdown doesn't behave correctly in simulation.

 

If you're on hardware then it could be that your 50MHz clock source isn't good enough. What is this clock source and is it clean with low jitter? Is this on a development board or your own hardware?

 

Cheers,

Alex

Длаза
Novice
188 Views

Well-well, in my project "pll_powerdown" is not connected inside fpll, but I made change to*.qsf-file (set_global_assignment -name VERILOG_MACRO "ALTERA_XCVR_A10_ENABLE_ANALOG_RESETS=1"), pll_powerdown is connected and "pll_locked" is OK!

Rahul_S_Intel1
Employee
188 Views

Please do not connect this pin through qsf file , connect through the IP .( Attaching the screen shot for your reference)

 

Rahul_S_Intel1
Employee
188 Views
posted a file.
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