Forum Discussion
Agilex E-TILE CPRI PHY
Hi Arik
'When dynamically reconfiguring the PMA to a different data rate, you need to recalibrate the PMA.'
Suspect your transceivers might not being properly calibrated. You can refer to Chapter 5 about PMA calibration in the E-tile Transceiver PHY IP User Guide.
https://www.intel.com/content/www/us/en/docs/programmable/683723/current/pma-calibration.html
5. PMA Calibration
The PMA is automatically calibrated when it is first enabled. When dynamically reconfiguring the PMA to a different data rate, you need to recalibrate the PMA. The PMA calibration is run when the PMA is enabled after a PMA analog reset, so you perform a PMA analog reset before requesting calibration. Refer to PMA Attribute Details for information on how to change PMA settings using the Avalon memory mapped interface. When referring to the PMA Attribute Codes section of the register map keep the following guidelines in mind:
• If you change any setting where 'yes' is indicated in the PMA Can be Running While Updating column, ensure that you do not disable the transceiver channel. If you disable the channel, then the transition of disable to enable initiates the
calibration and causes bit errors.
• If you change any setting where 'no' is indicated in the PMA Can be Running While Updating column, follow the following flow chart.
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Regarding the c3_reconfig.c file, you need to follow the steps in Figure 37 in section 4.1.2, which instantiate the 'E-Tile Dynamic Reconfiguration Suite' and generate the example design.
Link to '4.1.2. Generating the Design':
I have tried, and the c3_reconfig.c file is generated in ...\software\dynamic_reconfiguration_hardware\c3_reconfig.c
Hi skbeh
Thanks for your informative answer.
Regarding the Example design: before, I tried to generate it from the CPRI PHY IP itself and unfortunately it didn't produced the SW directory. However, now I tried the way in the link you suggested and generated the example design with the SW directory. So thanks a lot for that.
As for the PMA calibration. I tried it before and it didn't help.
The question is what is the exact procedure (with its the steps, 1 by 1, detailed) to change the line rate from LR8 which is 64/66 decoded (Gearbox 64/66 mode) to LR7 which 8/10 decoded (PMA Direct mode) and vice versa from LR7 to LR8. Should I only change the clock source (between 184.32 MHz and 153.6 MHz) and the CPRI PHY Register 0xC00 (between 0x9 and 0x6) and then do PMA calibration or there are more steps I need to do?
Best regards,
Arik