Programmable Devices
CPLDs, FPGAs, SoC FPGAs, Configuration, and Transceivers
Announcements
The Intel sign-in experience is changing in February to support enhanced security controls. If you sign in, click here for more information.
19679 Discussions

bandwidth / charge pump data setting registers

AEsqu
Novice
351 Views

Hello,

I use the avalon fsm to program the pll reconfig for a cyclone 5 FPGA.

I was wondering were I could find the bandwidth (address=8, 4 bits data) and charge pump (address=9, 3 bits data) setting registers

data values that corresponds to the settings indicated by the GUI of Quartus when creating a PLL.

For example, I do not know which register value is matching a charge pump current of 20 uA or a filter BW of 4000.

 

I cannot find a spreadsheet calculator (that the doc refers to) that would show me the register data values to write either on the Intel website.

 

I'm also wondering if it is necessary to write along with the c/m/n/k, .. parameters

those charge pump and bandwidth values (I was assuming that the PLL would keep the previous settings it had on power cycle, but I have the impression this is not the case when reconfiguring the PLL using the pll_reconfig block).

 

 

Kind Regards,

Alex.

0 Kudos
8 Replies
Farabi
Employee
299 Views
AEsqu
Novice
265 Views

Hello Farabi,

I can only select with the PLL reconfig calculator

a bandwidth setting of low (binary = 4'b1000)

but I'm not sure if medium is supported as well, is it not?

As for the charge pump, it is all black and nothing can be selected.

Am I missing something?

Alex.

 

 

AEsqu
Novice
212 Views

Some picture showing the bw selection from the Megawizard vs the only slow possible selection in the spreadsheet.

AEsqu
Novice
209 Views

Well, in the Megawizard, if I select low, medium or high BW,

they all end-up using 4000 Ohm resistor value.

So I guess that would explain why there is only one SLOW option value in the spreadsheet.

But it does affect the charge pump current.

When I select low BW, the charge pump current is 10 uA.

When I select medium BW, the charge pump current is 20 uA.

When I select high BW, the charge pump current is 30 uA.

What are the charge pump binaries values associated with 10, 20 and 30 uA then?

Alex.

 

AEsqu
Novice
172 Views

I see the value changing when trying to pick the box in the spreadsheet below low (is it medium then?)

low 10 uA would be binary values 010

medium 20 uA would be 100

high 30 uA would be ??? (spreadsheet keeps 100)

Farabi
Employee
144 Views

Hi Alex,

 

Referring to your PLL type, you are using integer-PLL, and at the spreadsheet, you need to select integer-PLL type. 

currently, you selected fPLL type in the spreadsheet and this is not align with your PLL type in Quartus. 

If the box turns black, that means you can't modify the parameter. 

 

regards,

Farabi

AEsqu
Novice
138 Views

Thanks Farabi,

I did not know I could change the PLL type.

After changing it I can see this:

low 10 uA  binary values are 3'b010

medium 20 uA binary values are 3'b011

high 30 uA binary values are 3'b100

Ticket can be closed, I can reprogram the PLL nicely with the avalon fsm.

Farabi
Employee
136 Views

Hi, 

I’m glad that your question has been addressed, I now transition this thread to community support. If you have a new question, feel free to open a new thread to get the support from Intel experts. Otherwise, the community users will continue to help you on this thread. Thank you.

 

regards,
Farabi

 

Reply