TPS65987D: I2C1 data not being sent to on Contract Negotiation Event

chris woodhouse

Part Number: TPS65987D
Other Parts Discussed in Thread: BQ25713,

I'm following this on from my previous post: https://e2e.ti.com/support/interface-group/interface/f/interface-forum/1001039/tps65987d-i2c3-as-master-not-working/3699964#3699964

We have progressed very little from above and the post was closed and locked before I had a chance to submit any of my findings.

To bring you up to speed:

We are using port I2C2 as a slave (and debug) and I2C1 as master (to the Charger: BQ25713)
To keep things simple:
- On POR and/or Hard reset we are configuring the charger as per the rows in green in the table below.
- We only have 2 contracts: 1 sink and 1 source, both are 5V, 3A
- We have only set up I2C master events for Sink PDO1. Upon successful sink contract, the input current to the charger will be limited to 3A
- Upon detach the charge current will be set to 0A and current limit into charger set to 500mA

Function	Addr	Initial Value	Description/settings
Charge Option 0	00	800E	Fixed initialisation
Charge Current Register	02	0000	Changes depending on Source available USB-C present = 0x0bc0 Not present = 0x0000
Charge Voltage Register	04	20D0	Fixed initialisation
OTG Voltage Register	06	09C4	Fixed initialisation
OTG Current Register	08	3C00	Fixed initialisation
Input Voltage Register	0A	0300	Fixed initialisation
Minimum System Voltage	0C	1A00	Fixed initialisation
Input Current Register	0E	0a00	Changes depending on Contract 0x0a00 - 500mA - No PDO 0x1E00 - 1.5A - PDO4 (NA) 0x2800 - 2A - PDO2 & 4 (NA) 0x3C00 - 3A - PDO0 & 3
Charge Status Register	20	8000	Read Back
Prochot Status Register	22	B800	Read Back
Input Current Limit In Use	24	4100	Read Back
VBUS and PSYS Voltage Read Back	26	3400	Read Back
Charge and Discharge Current Read Back	28	0000	Read Back
Input Current and CMPIN Voltage Read Back	2A	0000	Read Back
System and Battery Voltage Read Back	2C	0000	Read Back
Manufacture ID and Device ID Read Back	2E	E040	Read Back
Device ID Read Back	2F	00E0	Read Back
Charge Option 1	30	9300	Fixed initialisation
Charge Option 2	32	0077	Fixed initialisation
Charge Option 3	34	0434	0x0434 = NO OTG, 0x1434 = OTG Enabled upon Sink contract negotiation
Prochot Option 0	36	4A81	Fixed initialisation
Prochot Option 1	38	41A0	Fixed initialisation
ADC Option	3A	A07F	Fixed initialisation

The Problem

Firstly the POR/HR and Detach event data is being sent correctly (see below for Detach data and attachements for both events):

The POR data is considerably long and though it best to send a raw saleae file.

The issue comes when a contract is negotiated. When I enter debug mode on the PD controller, the Contract is active:

but when I inspect the I2C1 line to the charger, no data is sent on this event. Why is this?

I'm pretty Sure I have set up the master events correctly.

I should have attached all the relevant files, if there's anything missing please inform me ASAP.

Data Captures and Project Config.zip

over 4 years ago

0 Chuck Branch over 4 years ago

TI__Mastermind 32891 points

The TPS65987D does not send I2C traffic, it is a slave, your MCU will have to read the registers which is what the GUI is doing to provide the data shown.

If you have the I2C Interrupts configured to provide an interrupt when a source PDO or SINK PDO is available. I have highlighted the option to enable the interrupt when a new contract as provider is entered. There is a new contract as consumer option below it for the sink case.

This will cause the /IRQ1 line to pull low providing an interrupt to your MCU so that you can go read the Active Contract PDO (0x34) register to gain the same information.

0 chris woodhouse over 4 years ago in reply to Chuck Branch

Prodigy 100 points

Chuck Branch said:
The TPS65987D does not send I2C traffic, it is a slave, your MCU will have to read the registers which is what the GUI is doing to provide the data shown.

I'm sorry, but this just confuses us even more! If its a slave then why is there this application note (SLVAE18.pdf)? Can you clarify what you mean.

I will try and check that box in the Config tool and see if it works.

0 Ghouse Mohiuddin23 over 4 years ago in reply to chris woodhouse

TI__Expert 8170 points

The document refers to I2C1 or I2C3 which can behave as masters. I2C2 is where your MCU is connected and it is a slave.

0 chris woodhouse over 4 years ago in reply to Ghouse Mohiuddin23

Prodigy 100 points

chris woodhouse said:
We are using port I2C2 as a slave (and debug) and I2C1 as master (to the Charger: BQ25713)

we are NOT using I2C2 as a master, please see above for more clarification

0 Ghouse Mohiuddin23 over 4 years ago in reply to chris woodhouse

TI__Expert 8170 points

Chris,

I think there is little communication gap that we had. Basically your issue is that I2C1 as a Master is not working. I was just referring to your last remark on the I2C master application note. I think it is clear now. I will check with Chuck what he was trying to say, he is out of office this week.

Could you clarify this?

"The issue comes when a contract is negotiated. When I enter debug mode on the PD controller, the Contract is active:"

I didn't get why you needed to be in debug mode. If you have your configuration right, the contract should happen when you make a connection. I think we need to check if you are making correct PD contract and not just a Type-C only connection. Could you capture VBUS and CC1/CC2 (1.2V threshold, digital) and the I2C master traffic like you have in the picture.

0 chris woodhouse over 4 years ago in reply to Ghouse Mohiuddin23

Prodigy 100 points

The reason we are using Debug is to query the PD controller if it is activating a contract. if we look at the Active contract PDO register (0x34) in the Debug registers, it appears to have negotiated a contract.

Are we looking in the right place to confirm this?

I will see if I can get the CC lines and Vbus signals with the I2C1 data today.

0 chris woodhouse over 4 years ago in reply to Ghouse Mohiuddin23

Prodigy 100 points

This is the capture of the CC1, CC2 and VBUS when the USB-C cable is attached.

0 Chuck Branch over 4 years ago in reply to chris woodhouse

TI__Mastermind 32891 points

Chris,

Can you provide me with a screen capture of the Status register, so that I can see what Power delivery state the 987 has reached?

0 chris woodhouse over 4 years ago in reply to Chuck Branch

Prodigy 100 points

Hi Chuck,

Will try and get that to you soon.

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TPS65987D: I2C1 data not being sent to on Contract Negotiation Event

The Problem