DS90UB935-Q1: +DS90UB936-Q1 I2S simulation, GPIO0/1/2 forward channel configuration

Dongbao Zhou

Part Number: DS90UB935-Q1
Other Parts Discussed in Thread: ALP

HI Team,

Could you please verify the configuration code for 935+936 I2S transmission, 935 GPIO0/1/2 as input and only 1 camera in port0, 936 GPIO0/1/2 as output? We tried below code but it doesn't work.

936 >>>Write:

0x4C=0x01

0x0F=0x7D

0x10=0x01

0x11=0x05

0x12=0x09

935 >>>Write

0x33=0x07

0x0D=0x80

0x0E=0x87

Read back 0x53 (check input pin status)=0x02

Read back 936: 0x59=0x6b, 0xDC=0x02 and 0x0E=0x10 (check output pin status)

Appreciate you could share your feedback by today as it's very critical timing, many thanks.

Regards,

Dongbao

over 2 years ago

0 Dongbao Zhou over 2 years ago

TI__Expert 3930 points

Pls check whether there are typo for 936 0x10-16 register description, bit 5-7 should switch with bit 2-4. I solved the problem by doing this. 936 ALP register description is correct.

0 Nicholas Darash over 2 years ago in reply to Dongbao Zhou

TI__Mastermind 18755 points

Hello Dongbao,

It looks like on the 936 you are setting the GPIOs as inputs in register 0x0F when they should actually be outputs right? This seems to be working on my end though, are you able to probe the local GPIOs?

Regards,

Nick

+1 Dongbao Zhou over 2 years ago in reply to Nicholas Darash

TI__Expert 3930 points

Hi Nick，

You are right, it’s a typo for 936 0x0F configuration, it should be 0x78 actually but it doesn’t impact gpio1 pass through test, only gpio0/2 are impact.

We have to program 0x11=0x21 to make the gpio1 pass through work. If you test gpio0, this makes no difference because 0x11=0x01 which is not impacted by the datasheet typo (my assumption).

Pls take a look at 936 alp profile 0x10-16 description with datasheet, my test results show alp profile is correct.

Dongbao

+1 Dongbao Zhou over 2 years ago in reply to Dongbao Zhou

TI__Expert 3930 points

https://e2e.ti.com/support/interface-group/interface/f/interface-forum/992300/ds90ub936-q1-back-channel-gpio-mapping-support?tisearch=e2e-sitesearch&keymatch=954%252525252520gpio%252525252520map

I relook the datasheet and ALP profile description is same, but pls check above configuration, i am wired when i first saw it because it's not aligned with datasheet but it did work.

+1 Nicholas Darash over 2 years ago in reply to Dongbao Zhou

TI__Mastermind 18755 points

Hi Dongbao,

So are you not able to get anything through? Have you tried just holding the remote GPIOs high/low and probing the local GPIOs? Or is the only way you are testing if it is working is by reading the status register?

Regards,

Nick

0 Dongbao Zhou over 2 years ago in reply to Nicholas Darash

TI__Expert 3930 points

if i follow ds configuration，I get nothing out. Both gpio status reading and probe test are done to verify the gpio pass through function.

A quick way you can also check is the alp gpio configuration page and register page, it’s not aligned.

0 Dongbao Zhou over 2 years ago in reply to Nicholas Darash

TI__Expert 3930 points

Just noticed that it’s right description in datasheet but it’s not in a normal mapping.. thanks

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DS90UB935-Q1: +DS90UB936-Q1 I2S simulation, GPIO0/1/2 forward channel configuration