UCD9081: "UCD9081 GUI" can not find the device, but "I2C Device GUI" can, what can I do?

Yes, the I2C Device GUI see it as TPS54A50, please ignore it, you know the fusion tool doesn't support UCD9081 configuration, and I confirm my device is UCD9081.

The thing is the fusion tools can talk with my device on board, it says my device and board are not dead.

by the way, I also tried all available firmware of usb dongle(from1.0.10 to 1.0.14), same results.

If the device on board has been changed the address from 0x6F to 0x0F,is there any ways to change back to 0x6F?, 

is the pre-fix 0x60 fixed in device and can not changed? thank you !

Hello

I got a couple options for you to try out.

1. USB-TO-GPIO dongle is not powerup. Check to see whether the green led is on or not on the adapter

2. The USB-TO-GPIO settings are not right: it needs to be set to 100KHz and PEC disable.

3. The GUI is not installed properly. Uninstall and download https://www.ti.com/lit/zip/slvc490 to install.

4. Running the GUI as an administrator.

Also, the IC2 address for UCD9081 is between 0x60 to 0x6f. 0xf is not the UCD9081 and could be other devices on the same bus.

Hello SGradinaru,

the device is UCD9081, and I pull-up all address line physically on board, so the low byte of address word is 0xfh, the strange thing is the tps542a50 data sheet says it’s address is begin from 0x60h too, how can the GUI recognize the device as tps542a50 while the address is 0x0fh?

since the GUI and device can communicate and showed the log and the dongle setup information on the lower pane and status bar of GUI,  so don’t worry about if the dongle is working or not

I tried again, use I2C Device GUI tool, it always can talk with UCD9081(can not config as no correct UI), please check below log to see if it can help... appreciated!

Hi

The UCD9081 address starts from 0x60, the 4 Address pins make the address range from 0x60 to 0x6F. Please refer data sheet section 8.5.6. 0xF is not UCD9081. It shall be 0x6F since you have all address pin pull up.

You can follow use the lower level SMBus debuger to test, please following the below video to launch the debuger

https://training.ti.com/fusion-power-designer-low-level-i2c-smbus-debugger?context=1136655-1139495-1136567 

please ensure that the setting is 100KHz and PEC disable.

1. put 0x6F into the address

2. use the I2C read in the bottom of the debug, put 0x27 into the command, and put 0x1 into the len field, after clicking the read button, you shall receive 0x55. if not please hoop up the scope and provide the waveform.

Regards

Yihe

Hello Yihe,

Thanks for response.

I tried your suggestion, use the I2C SMBus debugger with scope hooked:

1, Read device at 0x6F with Cmd 0x27 (Len=0x1),  a red "NACK" displayed, please check below captures:

2, Read device at 0x0F with Cmd 0x27 (Len=0x1),  got Acked, but 0x41 returned, not 0x55, please check below captures:

The response duration of  returned 0x41 seems little strange, feel longer, almost missed  a 8-bit duration.

(100kHz and PEC disabled for all and always)

Please help to advice the next step...

Thanks for your time!

Hi

The address 0x6F is not available on the Bus since none ACKs the address. 0xF is other device on your bus. 

I would suggest to

1. check your board to make sure that UCD9081 has power, RESET is released, Address pins are good.

2. check your schematics to ensure that no other i2c device has the same address as UCD9081

3. try the same steps for address 0x60 to 0x6E to see which address get ACKed.

4. try to disconnect all other I2C devices on the same bus and repeat step 3.

Rgeards

Yihe

Hi Yihe,

Thank you , I only have one I2C device on board, it's a dedicated board to evaluate this UCD9081,  removed unnecessary components, remain power, decouple capacitors , pullups, and some other RCs according the typical circuit on the datasheet.

I measured supply, and reset pin voltage(high@10k PullUp and 0.01uF decouple), and put the 100Kohm Rosc very close to the Pin#32.

Tried  address from 0x60 to 0x6E ,  none-Acked.

What other registers I can try?

Thanks!

Hi 

it seems that UCd9081 was not functional in your board. Do you have a 9081 evm? Could you send us your schematic or you can compare your schematic with our 9081EVM to see anything missing?

Regards

Yihe

Hello Yihe, I don't have  a 9081 EVM, but I check the EVM user guide and schematics, please check my parts of schematics , thank you !

Hi

The schematics look good. How many boards do you have? Do they all have the same issue?

Could you do the following test:

1. provide the power up waveform of UCD9081: VCC, REST

2.  change one of the ADDR pin to pull down, so the address is not 0x6F anymore, do you still able to talk to 0xF address?

3. put the UCD9081 under reset(but has power), to see whether you can still talk to 0xF. As you mention, ucd9081 is the only device in the same bus.

4. disconnect the R127

5. replace the UCD9081 with another one.

Regards

Yihe

Hi Yihe,

please help to check the waveform, CH1 is VCC, CH2 is REST,  is it correct?

I also tried to pull down ADDR3, the device responsed the new address, not the old one,please review the screenshot, thank you.

disconnected the R127, same results.

currently, I don't have more units to replace,  not sure its configuration issue or the device is fail...

What address is when you disconnect R127? and what address is you connect R127? The UCD9081 GUI uses Address 60h to 6Fh to detect the device (I2C read at command code = 0x2F, and I2C read at command code = 0x27). If your device address is 0x0F, then it might not be the UCD9081.

Are there any devices, other than UCD9081 on the bus?

Using Fusion GUI low level debugging tool, try I2C read (with different addresses 60h:6Fh), 1 byte, command code = 0x2F to see if device response to I2C Read.

If device at address 60h:6Fh responses to the above command, then continue to I2C read, 2 bytes, command code = 0x27. 

Hi

Could you adjust VCC to have a fast slew rate?

When ADDR3 is pull down, what address can you talk to, 0xE?

Regards

Yihe

Hi Anne,

R127 and R128 connect to a 5V power the UCD9081 need to monitor, after the ADDR3 is pull down, 0x0B address can be recognized.

the address from 60h to 6Fh can not be reached.

Hi yihe,

VCC connect to the USB-GPIO Dongle's Pin#5, I removed the 1uF decoupe capacitor(remain a 0.1uF there), same slew rate same waveform.

Then I tried a external 3.3V power supply, slew rate much slow, need 5mS to reach 3.3V, but different waveform appeared on VCC and RESET pins:

After ADDR3 is pull down, the new address is 0x0B (1011b,11d) can be recognized, return the same 0x41 with 0x27 command on new address of 0x0B, while NACK on 0x6B.

Hi

That's very strange. Is this UCD9081? Could you take a picture of the top marking?

Regards

Yihe

I don't it's fake part or not

Hi 

Could you answer below questions?

1. How many units have these problem?

2. Where do you purchase these devices?

Regards

Yihe