TMUX1574: SPI load fail issue

Patrick Chen

Part Number: TMUX1574
Other Parts Discussed in Thread: SN74CB3Q3257

Hello

Customer use BMC->U119 SPI mux-> load SPI flash and use another path I/O card->U549->U119-> load SPI flash.

U119 is TMUX1574 and load SPI flash code is fail. But if change U119 to SN74CB3Q3257. SPI Flash code is loaded successfully. Why is the issue rot cause and the difference? Attached is testing waveform. Thank you.

Sparrow_09112019.rar

over 4 years ago

0 Saminah C over 4 years ago

TI__Genius 9132 points

What is the voltage supply you are using for both switches? What is the maximum SPI clock signal frequency?

Any reason why you are using two different types of switches SN74CB3Q3257 and TMUX1574?

The TMUX1574 device was specifically designed for SPI mux applications and has a wide operating voltage and 1.8V compatible control logic which makes it suitable for many applications including multiplexing SPI lines.

I am reviewing the scope shots and get back to you with more details.

Thanks

Saminah

0 Patrick Chen over 4 years ago in reply to Saminah C

Mastermind 8875 points

Hello Saminah

Supply voltage is 3.3V and 50MHz. if used U119 3257 , BMC load SPI Flash code is fail. But U119 change to TMUX1574 from 3257 . BMC load SPI flash code is successful. We will send compare waveform between TMUX1574 and 3257 later. Thank you.

Patrick

0 Patrick Chen over 4 years ago in reply to Patrick Chen

Mastermind 8875 points

Hello

Attached is customer issue description and testing waveform. Has any comments for this issue? Thank you.

PatrickIssue Description.pptx

0 Saminah C over 4 years ago in reply to Patrick Chen

TI__Genius 9132 points

Hi Patrick,

Thank you for sharing the details.

Looking at the waveforms you shared, we still need some more information to understand the issue.

Is it possible to share the following information:

Board Layout
Part No. (other than TI switches you have in the schematic)
VIH and VIL for the flash parts
Drive Strength and rise time

You can share the information via email if that works better.

Thanks

Saminah

0 Patrick Chen over 4 years ago in reply to Saminah C

Mastermind 8875 points

Hello Saminah

Thanks. We will update the above information while get it from customer Could you help provide your email to me? Thank you.

Patrick

0 Saminah C over 4 years ago in reply to Patrick Chen

TI__Genius 9132 points

Sure. please share details at saimnah_c@ti.com.

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TMUX1574: SPI load fail issue