CCS/DS90UB902Q-Q1: DS901 and DS902 GPIO pin for UART

Hi,
GPIO is used for transparently transmitting the signal from one side to the other side unfortunately it can't be identified as "idle", you can program it as high with external pull-up resistor during "idle" cycle.

regards,
Steven

Hi
Do You mean the inital state of the GPIO do not effect the UART communication?
If I do not using the external pull-up resistor during 'idle' cycle,
Could the UART communication work well?

OR
if I used the GPIO[0:1] as the UART
Should I pull this two pins as high with external pull-up resistor.

Other question is that:
Can I debug the UART communication with out the vedio date transmission

1. pls note FPD-Link provides the GPIO function NOT for UART protocol application. in other words, any level status in local GPI pin can be transmitted to the remote GPO pin transparently.
2. refer to above item1, the GPIO is for I/f only. if you run the UART, you should secure the UART PHY level can be met in the link application.

best regards,
Steven

Hi

Then I connect the 901 and 902 as the figure I showed

I set The 902 register to configure the GPIO[1:0] as input pin as follow
registerID Value
0x1D 0x17
0x1E 0x07

I set the 901 register to configure the GPIO[1:0] as ouput pin as follow
registerID Value
0x0D 0x11
0x0E 0x01

Then I pull up the 902 GPIO[1:0] pins by configure TDA3x pins which connect to 902 GPIO[1:0] pins,
waiting a moment then push down the 902 GPIO[1:0] to generate the wave .

But I can not capture the wave in DS901 GPIO[1:0]

So How Can I fix it？

Thank you

The more information as follow:
1. And I can capture the wave in the DS902 GPIO[1:0] which as the sending end！
2. The DS901 and DS902 as the salve mode, The Local ECU or FPGA configure the register
3. The FPD_LINK is ok to transport the vedio

For your new request, it is the remote GPIO function issue. the setting of your provisioning is correct. can you check whether the remote I2C can work or not? how about the backchannel error 0X0A/0X0B?
btw, which project do you use? now UB933/UB934 are popular in the market as camera serdes.



best regards,
Steven

Hi
The 0x0A and 0x0B is 0xFF

the setting is right.

Steven

But is not work

Hi,
sorry we have on 901/902 EVM board in hand as these two devices were released for long time.
is it possible to ship one system to us for more test? the I2C pins can be pulled out for test.

best regards,
Steven

How can I ship to you? maybe you can send a EVM demo board for us to test!
My addr is 4th Floor, Building B15, Guanggu Software Park, Hongshan District, Wuhan, Hubei, China
Thank you very much