DS92LX1621: GPIO does not work

toshi-e2e

Part Number: DS92LX1621
Other Parts Discussed in Thread: DS92LX1622,

Hi all,

In the case without using I2C,
even if "1" is set to GPIO (0) of DS92LX1622 "1" is not output to GPIO (0) of DS90LX1621.
The LOCK output of the DS92LX1622 is high, so the link may be established.

Looking at the initial value of the registers, the GPIO (0) of the DS92LX1621 is set to output, and the GPIO (0) of the DS92LX1622 is set to input.
So I think that it will operate in the initial state if LINK is established.

Please tell me how to solve GPIO not working.

How should I process each M/S pin and I2C pins when I do not use I2C I/F?

Regards,
Toshi

over 7 years ago

0 toshi-e2e over 7 years ago

Genius 4830 points

Hi all,
I have an additional question.

According to the datasheet, Reg (0x27: BCC) of DS92LX1622 should be programmed 0xE0 for normal operation mode.
If GPIO is used, is it necessary to set this register?

Regards,
Toshi

0 Ikechukwu Anyiam over 7 years ago in reply to toshi-e2e

TI__Mastermind 35130 points

Hi Toshi-san,

Are you able to read the control registers and confirm that the GPIO[0] registers are set at the default values?

Regards,
I.K.

0 toshi-e2e over 7 years ago in reply to Ikechukwu Anyiam

Genius 4830 points

Hi I.K.-san,
Thanks for your reply.

As my customer's information, they do not use I2C I/F and it's impossible to read the control registers.
Also they set both M/S pins to GND.

Best regards,
Toshi

0 Ikechukwu Anyiam over 7 years ago in reply to toshi-e2e

TI__Mastermind 35130 points

Hi Toshi-san,

Sorry for the delay. Setting both M/S pins to GND sets both devices up as I2C masters. Can they try the below scenarios to see if it resolves the issue?:

1. Display Mode (1621 M/S = Low, 1622 M/S = High)
2. Other (Both 1621 and 1622 set to High)

Regards,
I.K.

0 toshi-e2e over 7 years ago in reply to Ikechukwu Anyiam

Genius 4830 points

Hi I.K.-san,
Thanks a lot for your reply.
I will inform your answer to my customer. Also I will ask them to try I2C communication for accessing registers.

0 toshi-e2e over 7 years ago in reply to toshi-e2e

Genius 4830 points

Hi I.K.-san,
They tried to connect both M/S pins to HIGH like No 2. case (2. Other (Both 1621 and 1622 set to High)).
But still GPIO did not work.

Is it necessary to set REG0x27(BCC) of DS92LX1622 to 0xE0?

Regards,
Toshi

0 Ikechukwu Anyiam over 7 years ago in reply to toshi-e2e

TI__Mastermind 35130 points

Hi Toshi-san,

What about No 1. case?

And yes, please set REG0x27 to 0xE0.

Also, do you know if the customer is using our EVM? It looks like there was a similar issue here and the problem had to do with an RJ45 to SMA adapter board: e2e.ti.com/.../997030

Regards,
I.K.

0 toshi-e2e over 7 years ago in reply to Ikechukwu Anyiam

Genius 4830 points

HI I.K.-san,
They do not have the EVM and have been evaluating on their own designed system.

According to their report,
both M / S pins remains high and the Forward channel is working well. BCC register (REG0x27 ) is also set.
But still GPIO does not operate even under that condition.
Is there anything they have forgotten to set up elsewhere?

Or the devices must have complementary settings for the M/S configuration?
If yes, they plan to modify their board and will try to Camera mode or Display mode later.

Regards,
Toshi

0 Ikechukwu Anyiam over 7 years ago in reply to toshi-e2e

TI__Mastermind 35130 points

Hi Toshi-san,

Sorry for the delay, I am still looking into this and will update you as soon as able.

Regards,
I.K.

0 Ikechukwu Anyiam over 7 years ago in reply to toshi-e2e

TI__Mastermind 35130 points

Hi Toshi-san,

I believe it would be best to try camera mode and display mode as the devices may need to have complementary settings for the M/S configuration. Other than that I don't see anything incorrect about their setup.

Regards,
I.K.

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DS92LX1621: GPIO does not work