DP83822H: Simultaneous output 50 MHz to GPIO2 and GPIO3

Petr Tokar

Part Number: DP83822H

Hello friends,

I did not find in DP83822 datasheet ...
Is DP83822 capable to output 50 MHz clock to GPIO2 and GPIO3 simultaneously ?
I'm going to use RMII master mode and input 25 MHz oscillator to XI and get 50 MHz from GPIO2 and GPIO3

Thanks,

Petr

over 4 years ago

0 Cecilia Reyes over 4 years ago

TI__Genius 9920 points

Hi Petr,

What is the reason for having the 50MHz output for both GPIO pins?

Thanks,

Cecilia

0 Petr Tokar over 4 years ago in reply to Cecilia Reyes

Prodigy 40 points

Hello, Cecilia

One output - RMII REF_CLK on MAC

second - main MCU clock

Petr

0 Cecilia Reyes over 4 years ago in reply to Petr Tokar

TI__Genius 9920 points

Hi Petr

Would it not be possible to share the output to two lines or is there an output ref clock on the MAC to connect to MCU?

I am unsure of a use case where 2 outputs were 50MHz clock so i will have to investigate and see if it is possible.

Thanks,

Cecilia

0 Petr Tokar over 4 years ago in reply to Cecilia Reyes

Prodigy 40 points

Hi Cecilia
Thank you for the reply

My MCU is stm32f107RCT6

I'm going to use one 50 Mhz output of DP83822 (GPIO2) as ref clock for MAC (pin REF_CLK/PA15 on MCU)
and the second (GPIO3) - as main clock of MCU (pin PDO_OSC_IN on MCU)

Best regards,
Petr

0 Cecilia Reyes over 4 years ago in reply to Petr Tokar

TI__Genius 9920 points

Ok, thanks Petr. I will need to investigate this further and get back to you.

Thanks,

Cecilia

0 Cecilia Reyes over 4 years ago in reply to Cecilia Reyes

TI__Genius 9920 points

Hi Petr - as long as you are configuring both outputs through register configuration this looks to be possible

Thanks

Cecilia

0 Petr Tokar over 4 years ago in reply to Cecilia Reyes

Prodigy 40 points

Thanks,

Happy New Year !

0 Cecilia Reyes over 4 years ago in reply to Petr Tokar

TI__Genius 9920 points

Thanks, you too!

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DP83822H: Simultaneous output 50 MHz to GPIO2 and GPIO3