AM437x UART clock

Hiroyasu Tazawa1

Guru 12350 points

Hi, Everyone

I have a question about UART of AM437x.

UART clock generation is describ in 21.3.8.1.1 UART Clock Generation:
Baud Rate Generati on AM437x's TRM.

I see RX and TX clock is difference.
Can you tell me why it is difference ?

Best Regards
Hiroyasu

over 8 years ago

0 Biser Gatchev-XID over 8 years ago

TI__Guru**** 393215 points

Hi,

This is because UART receive is done at 16x or 13x oversampling.

0 Hiroyasu Tazawa1 over 8 years ago in reply to Biser Gatchev-XID

Guru 12350 points

Hi, Biser

Thank you !
I understand TX/RX will be set difference clock.
My customer want 625[kbps].
and They calcurate below.

615.38[kbps] = 48[MHz] / 6(DLH,DLL) / 13(MDR1)

I think RX/TX clock are diffrence in this case.
This understanding is correct ?

Best Regards
Hiroyasu

0 Biser Gatchev-XID over 8 years ago in reply to Hiroyasu Tazawa1

TI__Guru**** 393215 points

No, both RX and TX data will be at 615.38kbps. However RX data will be oversampled at 615.38 * 13 = 7.99994MHz.

0 Hiroyasu Tazawa1 over 8 years ago in reply to Biser Gatchev-XID

Guru 12350 points

Hi, Biser

Thank you!
I got it.

Best Regards
Hiroyasu

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AM437x UART clock