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Changing JESD Lane Rate

Thread Summary

The user encountered CPLL RX buffer underflow and overflow errors after reducing the number of Tx JESD lanes from 8 to 4 and dropping the sampling frequency from 491.52 MHz to 245.76 MHz while maintaining a lane rate of 9.83 Gbps. The solution involves referring to a specific forum post for detailed configuration adjustments and troubleshooting steps for the ADRV9009 and related device tree settings.
AI Generated Content
Category: Software
Product Number: ADRV9009

Hello,

A customer intends to reduce the number of Tx JESD lanes from 8 to 4 and drop the sampling frequency from 491.52MHz to 245.76MHz and maintain a lane rate of 9.83Gbps.

What changes are needed to the HDL and SW?

We suggested updating the device tree, and the customer made these changes:

&trx0_adrv9009

{     adi,tx-profile-dac-div = <2>;     adi,jesd204-deframer-a-deserializer-lanes-enabled = <0x3>;     adi,jesd204-deframer-a-deserializer-lane-crossbar = <0x4>;     adi,tx-profile-tx-input-rate_khz = <122880>; }

;

&trx1_adrv9009

{    adi,tx-profile-dac-div = <2>;    adi,jesd204-deframer-a-deserializer-lanes-enabled = <0x3>;    adi,jesd204-deframer-a-deserializer-lane-crossbar = <0x4>;    adi,tx-profile-tx-input-rate_khz = <122880>; }

;

&axi_adrv9009_tx_jesd

{     adi,octets-per-frame = <4>; }

;

But they receive this error:

[  417.906182] axi_adxcvr_drv 84a60000.axi-adxcvr-rx-os: adxcvr_clk_enable: CPLL RX buffer underflow error, status: 0x61

[  417.916804] axi_adxcvr_drv 84a60000.axi-adxcvr-rx-os: adxcvr_clk_enable: CPLL RX buffer overflow error, status: 0x61

Any insight into what they need to do differently?