UCD90320: UCD90320 connection to PC using USB2ANY + general doubts

Ashwath Hegde9

Intellectual 350 points

Part Number: UCD90320

Hi,

I wanted to know how the polling actually works. Where are the digitised values of analog voltage is stored ?

Are there any PMBus commands to access those values via I2C link.?

I wanted to know whether there is any provision to set a particular bit in the RAM.

Current scnario:

I'm getting an external signal to UCD90320 landing on a GPIO which indicates the power down sequence to start.

Once the power down completes I want the external software to know about it. But I dont want to drive Pins for that (like any GPOs or LGPOs) i.e I dont want to convey this via analog output.

After the power down I want to set any bit (indicates power down sequence is completed), which external software can access via PMBus commands and I2C link.

In short is there any provision to latch a value in any registers..??

If its possible whats the PMBus command/s for the same.

I wanted to know what is actually happening in this.I'm attaching a snap.

Like what is the meaning of those parameteres,Last value and last raw .

Explain to me for one of the readings say

7. RAED_VOUT [0X88,RAIL #7]...................

How does DMON works. Your docs says

What voltage is Logic High to a DMON pin.? How to set that voltage.

I'm not getting any options to do the same.

PMBus commands to read

a) Logged faults

b) black box content

c) status reg of rails

Thanks and regards,

Ashwath.

over 7 years ago

0 Weidong Zhu over 7 years ago

TI__Expert 5965 points

Hi,

We will review these questions and get back to you soon.

Regards,
Weidong

0 Ashwath Hegde9 over 7 years ago in reply to Weidong Zhu

Intellectual 350 points

Hi,

Please resolve it asap. Unless these things get clarified I cant move further in the project.

Regards,
Ashwath.

0 Anne Ngo77 over 7 years ago in reply to Ashwath Hegde9

TI__Genius 9320 points

1. Polling is query the telemetries (READ_VOUT, READ_IOUT, etc.) and status parameter (STATUS_WORD, STATUS_VOUT, etc.) per pages. Please refer to http://www.ti.com/lit/ug/slvuaw9a/slvuaw9a.pdf for detail

2.Access PMBus Command through i2c link: you can use I2C command to send PMBus commands, you just need to format the data according to the I2C Spec. Please refer to I2C spec of how to format data: https://www.i2c-bus.org/specification/

No, you can not set a bit in RAM to indicate the sequence complete. Device will set it for you. If you would like to have something indicate the sequence complete, query RAIL_STATE (0xB9), or use EN pin. Please refer to http://www.ti.com/lit/ug/slvuaw9a/slvuaw9a.pdf for detail.

3. Please refer to #1 regarding polling. The raw data is the binary data received from device (for example 0x01FAC2). The latest value is the decoded value for what it mean. For example, READ_IOUT raw data is 0x0000, is interpreted as 0.00 A. Please refer to http://www.ti.com/lit/ug/slvuaw9a/slvuaw9a.pdf for detail

4. You can use a DMON to monitor voltage. However, there are only 2 values for DMON (Digital Monitor): 1 (or High) mean Power Good. 0 (or Low) mean Power Off. Since there are only 2 values, there is no profile for the rail. Please refer to http://www.ti.com/lit/ug/slvuaw9a/slvuaw9a.pdf for detail.

5. Please refer to http://www.ti.com/lit/ug/slvuaw9a/slvuaw9a.pdf for how to read/write PMBus Command. Also I2C, SMBus and PMBus: https://www.i2c-bus.org/specification/ , http://smbus.org/specs/smbus20.pdf , http://pmbus.org/Home

0 Ashwath Hegde9 over 7 years ago in reply to Anne Ngo77

Intellectual 350 points

In 4th you told that DMOn can be used to monitor voltage. I know that there can be on;y 2 states in it. But on what criteria it defines a particular voltage as HIGH or LOW.
Ex: Say for me 2.5 V is HIGH and -1 V is LOW. For some one else this voltage levels can be different depending on the I/O standards.
How it differentiates these two situation.

To be specific if I'm supplying a voltage of 1V to DMON1 what will be its state? HIGH or LOW?

Can u just give me an example where DMONs can be used?

Regards,

Ashwath.

0 Anne Ngo77 over 7 years ago in reply to Ashwath Hegde9

TI__Genius 9320 points

The DMON pins are actually GPIO pins, so they will have voltage level as defined in GPIO pins. To be specific, 1V is applied to DMON, it is considered LOW state.

0 Ashwath Hegde9 over 7 years ago in reply to Anne Ngo77

Intellectual 350 points

Hi,

How to define voltage voltage levels for GPIO pins.?

Only options that I can see is Active Low or HIGH.??

Now if I to set HIGH logic as 2.5V and LOW logic as -2V how to set this for DMON

Consider I have 2 rails r1 and r2.

r1-

a)on/off config- control pin only

b)sequence on/off dependancy-r2

r2-

a)on/off config-auto enable

b)sequence on/off dependency-none

Now if a fault causes r1 to shutdown will it shuts down r2 as well (because its n auto enable )

What is the criteria for DMON railto be in POWER GOOD or NOT POWER GOOD.?

How does it creates any faults and fault shutdowns eventually.??

I want more details on auto enable feature

Thanks and regards,

Ashwath.

0 yihe over 7 years ago in reply to Ashwath Hegde9

TI__Guru 66120 points

1. Please refer the data sheet to understand the voltage level of GPIOs.
2. r2 has to be set a fault shutdown slave of r1 and the fault response of r1 is not set to ignore and continue operate.
3. DMON is the same as GPIO and it follow the GPIO voltage defined in the data sheet.
please refert the document in my signature.
Regards
yihe

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UCD90320: UCD90320 connection to PC using USB2ANY + general doubts