DS90UB947-Q1: register value is abnormal

Hi Sam,

Sam Sun said:

experienced a failure during the experiment of engineering change

Can you describe the failure that is seen from the system?

• Is this a screen abnormality?
• How many units are affected out of how many units total?
• Does this happen on every cycle, what is the % this test will fail?
• What are the temperature ranges seen in the system test?

The registers that are being read here are from indirect access, specifically the OLDI Page.

• From the images, it appears these reads are the same (is the image accidentally uploaded twice?)

Are other registers affected by the read?

Best,

Miguel

6 experimental samples, 2 of which malfunctioned;
Phenomenon 1: During the cold and hot cycling (cycling in the range of -30 ℃ to 80 ℃) test, the sample shows no backlight on the screen (appearing in the 80 ℃ range), and the temperature will return to normal when it decreases;
Phenomenon 2: When the sample is cycled between -30 ℃ and 80 ℃, there is a phenomenon of no backlight on the screen during startup at -30 ℃; The gradual increase in temperature is the elimination of the fault;
After assisting in replacing one 947, the fault disappeared but did not reappear, and the fault followed 947.

Hi Sam,

Two questions for clarification:

1) What is the relation of the backlight to our 947 device?

• Is it enabled / connected via 947 GPIO?
• Is there an additional or other circuit connected from the 947 to the backlight (seems this would be more of a DES side config)?
• Maybe a block diagram would help us understand this further

2) Have these units already been submitted to QUEM / quality return or ATE testing?

• This is recommended since the issue follows 2 devices out of 6 when replacing the units

Please let me know if there is any additional information that may be helpful for the case, but for now the above may help debug this phenomenon.

Best,

Miguel

1. When there is a problem, the backlight can be seen to be bright, and it also has a touch effect; It's just a display issue; 2 a、 The problematic machine replaced the surrounding materials of the 947 circuit once and re experimented, but the experiment still reproduced; b、 Comparing the values read from the register of 947, it was found that the machine with the problem is different from our batch shipment status machine; c、 After turning on the machine normally and creating an environment of 80 ℃, if there is a phenomenon of no display, it will be restored to normal display when it is warmed up again; The problem of returning to 80 ℃ has reappeared

Hi Sam,

Just to confirm:

Sam Sun said:

2 a、 The problematic machine replaced the surrounding materials of the 947 circuit once and re experimented, but the experiment still reproduced

1. The 947 is connected to the backlight function via GPIO or other configuration?

Sam Sun said:

Comparing the values read from the register of 947, it was found that the machine with the problem is different from our batch shipment status machine

2. Which registers are changed between the failing ICs and the passing ICs?

Sam Sun said:

80 ℃, if there is a phenomenon of no display

3. Meaning there is a black screen with display turned on, or the back light is not enabled at all?

Thank you for providing further clarifications, in the meantime have the parts been submitted to quality analysis already?

Best,

Miguel