DS90UB948-Q1: DS90UB948-Q1 AS A Switch For 2 Devices

Bright Wang40

Intellectual 540 points

Part Number: DS90UB948-Q1
Other Parts Discussed in Thread: DS90UB927Q-Q1

My Question Is If We Have 2 Devices As Video Links To 1 DISPLAY TOUCH COMBO Module As Below

How Can We Control DS90UB948-Q1 For Either Of Links When I2C Is Occupied By Touch Controller To MPU?

Is That Possible Use GPIO: OPEN LOW / ACTIVE HIGH To Control DS90UB948-Q1?

over 8 years ago

0 Bright Wang40 over 8 years ago

Intellectual 540 points

OR
Can I Use GPIO To Be Serialized By DS90UB927Q-Q1 To Control DS90UB948-Q1 For Either Of Video Links?

0 Palaniappan Manickam over 8 years ago in reply to Bright Wang40

TI__Genius 10475 points

Hello,
This thread has been assigned for an Apps person to look at and respond to.

0 Bright Wang40 over 8 years ago in reply to Palaniappan Manickam

Intellectual 540 points

THANK YOU VERY MUCH.

Due To The Emergency Of Our Working Project And Here Is Not Lesser Time Left In Our Roadmap So We Really Do Need Your Helps For The Part.
The Following Screenshot Are Captured From DS90UB948-Q1 Page 64 / 67. According To The Register Map It Seems Can Be A Switch.

0 Steven(Shenzhen) Shi over 8 years ago in reply to Bright Wang40

TI__Mastermind 30515 points

Brght,

yes, the block diagram can work. Please take care for below two points:

1. UB948 can accept either the primary input (from one UB927) or the second input (from the other UB927), but the display panel can NOT display both UB927's inputs in the same time;

2. The I2C channel between UB927 and UB948 (and its remote I2C slave) can work well through back channel link.

best regards,

Steven

0 Bright Wang40 over 8 years ago in reply to Steven(Shenzhen) Shi

Intellectual 540 points

Hello Steven
Thank You For Your Reply. I Just Want To Make Sure "2 Lane FPD-LINK III Input / Single Link OpenLDI Output "In The Device Functional Mode Is
Either Selecting One From 2 Inputs For An OpenLDI Output / Merging 2 Input s For An OpenLDI Output. It's Kindly Different. The Former Means 2 Input Data Paths To Be Pipeline Into Single Output And The Latter Means "2 Input Data Paths Only Allow Either To Be An Output". According To Your Answer To Our Block Diagram We Now Can Definitely Use DS90UB948-Q1 As Switch For Either Of 2 DS90UB927Q-Q1 Base Devices.

And Here Are My Last Questions About DS90UB948-Q1. In Datasheet Page 6 - 7 As Following Screenshot:

What Are The REGISTER READ/WRITE ONLY GPIO PINS From GPIO5 ~ GPIO8_REG GPIO For? What Are They Different From MODE_SEL PIN?

To My Understanding The MODE_SEL Pins Are For Device Functional Mode Selection Like Below. Am I Right?

And If I Want To Control The DS90UB948-Q1 I Shall Use GPIO5_REG ~ GPIO8_REG Right? Because Only The Specified GPIOs Are Capable For Read / Write Register?

What Is PORT_SEL For And What Are The Pins Can Be Configured For PORT_SEL?

What Is Different From D_GPIO And GPIO And GPIO_REG?

Thank You Very Much

0 Steven(Shenzhen) Shi over 8 years ago in reply to Bright Wang40

TI__Mastermind 30515 points

Bright,
sorry I can't understand your question clearly. please note:
1. if you use "2lanes+OpenLDI output" of UB948, you must the pairing part UB947 or UB949 which have 2 lanes output;
2. if you use 2x UB927 to pair with UB948, ONLY one UB927 can work in one time. And the 2pcs UB927 output can NOT be mixed together.

Regards,
Steven

0 Bright Wang40 over 8 years ago in reply to Steven(Shenzhen) Shi

Intellectual 540 points

Yes Your Answers Are Same With Mine.

I Asked That Again Is For A Final Confirmation.

Because I Think It DS90UB948-Q1 Can Be Configured As A Switch For 2 DS90UB927Q-Q1 Devices But Distributor's FAE Tell Me No It's Incapable Of Doing That. From Your Answers And Our Design And Datasheet I'm Now Pretty Sure The DS90UB948-Q1 Can Be Set As Switch By Mode_Select And GPIO_Reg.

0 Steven(Shenzhen) Shi over 8 years ago in reply to Bright Wang40

TI__Mastermind 30515 points

Ok, please trust the d/s. :)

regards,
Steven

0 Bright Wang40 over 8 years ago in reply to Steven(Shenzhen) Shi

Intellectual 540 points

Steven

My Final Question Here:
Can I Use PWM Through GPIO LINK From 927 To 948? If I Can Is There Any Limitation?

Thanks

0 Steven(Shenzhen) Shi over 8 years ago in reply to Bright Wang40

TI__Mastermind 30515 points

Sure, please note the PWM rate due to the back channel limitation.

regards,
Steven

0 Bright Wang40 over 8 years ago in reply to Steven(Shenzhen) Shi

Intellectual 540 points

So What Is The BCC Limitation If I Use BCC For I2C Interface For A Link Between Main Processor And Touch Controller Through FPD-LINK III DS90UB948-Q1 Already. What Is Your Suggest For Both Of I2C / PWM Rate Set? Note Here Is No SPI BCC Enable Nor I2S. Only GPIO / DGPIO / I2C / PWM.

0 Steven(Shenzhen) Shi over 8 years ago in reply to Bright Wang40

TI__Mastermind 30515 points

Bright,

as one general rule, it has ~10us uncertain propagation delay due to back channel limitation. so you need care for it if you are designing the PWM's available pulse.

regards,

Steven

0 Bright Wang40 over 8 years ago in reply to Steven(Shenzhen) Shi

Intellectual 540 points

Steven

Appreciate Sincerely. Your Answers Shall Be Good For Us To Accelerate Project.

Interface

Interface forum

DS90UB948-Q1: DS90UB948-Q1 AS A Switch For 2 Devices