Receive – DP159 Related Issues - 2.1 English

This section contains debugging steps for issues related to DP159. Proper operation of DP159 is essential for the training to complete successfully.

• IIC checks:
  • Check if the IIC speed is 400 kHz or higher speed (1 MHz).
  • Check if the IIC writes are happening properly to the DP159 IC.
  • Check if the IIC writes are interrupt or polling based. If it is interrupt based, it would be like calling an interrupt within another interrupt routine. Make sure this function correct, or better to go with polling mode, as DP159-IIC writes are supposed to happen at DP training events.
• Until the training is done make sure only the TP1 and TP23 interrupts are enabled.
• Ensure that you have no other software code in between TP1 interrupt to training done duration.
• Check whether the TP1 and TP23 handlers are called correctly when the TP1 and TP23 interrupts are detected.
• Ensure that the selection of the reference clock is correct in the Video PHY.
• Probe the lnk_clk output and check the SI of the Clock is within the Phase Noise mask of the respective GT.
• Avoid using PRINTF to monitor the DP159 configuration as the configuration must be completed as quickly as possible in order to meet the DisplayPort Standard requirements.