DS90UB948-Q1: Urgent: Configuration of mode_0, mode_1 and IDX through registers?

Hello Charles,

Yes, each function that is strapped by MODE_SEL (MAP_SEL, Output Mode, Repeater, back channel speed, and input mode) can be overridden through registers after power up

Best Regards,

Casey 

Hi Casey,

Let me rearrange my understanding.

1. Do you mean we can replace the function of mode_SEL0 OR mode_SEL1 pin simply by register configuration? What's the corresponding register than?

1. Do you mean we can replace the function of IDX pin simply by register configuration? What's the corresponding register than?

Hi Pial,

• MODE_SEL0 impacts FPD_TX_MODE Register (Address = 0x49) 

Can you confirm the function of  MODE_SEL0 can be configured by FPD_TX_MODE Register?

• MODE_SEL1 impacts RX_MODE_STATUS Register (Address = 0x23

Can you confirm the function of MODE_SEL1 can be configured by RX_MODE_STATUS Register?

Hi Pial,

For IDX, I am concerned that the default value of  I2C_DEVICE_ID Register is same? Than how do I identify the different device by different address if IDX is not used or the configuration of IDX is same and through only register configuration.

Hello Charles,

Please check the datasheet and let me know if something is not clear, but yes, except if I am missing something, mode configured by these pins can be overrided by the registers I mentionned.

Sorry but I just don't understand your question for the I2C.. ? The default value loaded in the register depends on the IDX pin, this should offer you enough flexibility, even in a very large system with multiple serializers.

Best regards,

PA

Hi Pial,

My customer wants to confirm  that whether it is OK to use the same IDx configuration and use registers instead to identify different device? Is there no problem about this when power up?

well... if all the devices are turned ON with the same IDX setting == same I2C address, and if they are connected to the same I2C bus on the board, then yes, I believe it's likely to be a problem.

Hi Pial,

Thanks for your reply and I am sorry for that I am not familiar with this device.

So we can use different configuration of IDX to power up device and then revise them by I2C_DEVICE_ID Register for any different address?

Hi Charles,

Yes this is how I would proceed: having a different setting on each device for the IDX pin, that way they all start with a unique address.

Then, if your customer wants to override the setting, it is up to them!

Best regards,

PA

Hi Pial,

One more question, in the above reply, you have mentioned that

• MODE_SEL0 impacts FPD_TX_MODE Register (Address = 0x49) 
• MODE_SEL1 impacts RX_MODE_STATUS Register (Address = 0x23) 

Are there any problems if we use the same configuration of MODE_SEL0 and MODE_SEL1 when power up and then revise the FPD_TX_MODE andRX_MODE_STATUS register later?