CYBT-343026 UART baud rates

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NiPa_3775556
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10 replies posted 5 replies posted 5 questions asked

Hi,

I'm trying to interface to the CYBT-343026 HCI UART at as fast a speed as possible but the processor I am using cannot hit the 'common' baud rates exactly. I'm trying to understand what baud rates the CYBT-343026 can produce but the documentation is not very clear. In the datasheet there is an 'HCI UART Interface' section with a table for 'Common Baud Rate Examples, 24 MHz Clock' but it is unclear how the numbers result in the quoted baud rates especially since a few rows have the same settings but produce different baud rates (e.g. 4M and 2M or 115200 and 57600).

How can I work out what other baud rates can be supported so that I can work out the percentage error between the Bluetooth module and the controlling processor?

Thanks

Nigel

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3 Replies
Owen_Zhang123
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5 questions asked 500 solutions authored 250 sign-ins

The 343026 is a 20706-based module, you can find the common baud rate examples in the datasheet table 2 and table 3: CYW20706 Datasheet

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Hi Nigel,

To be clear, do you want to change the HCI UART baudrate?

By default, it is 115200. Please refer /20706-A2_Bluetooth/platforms/CYBT_343026_EVAL/wiced_hal_platform.h.

Hi,

I am already setting the baud rate using the baud rate field within the wiced_transport_cfg_t structure. My problem is I have no way of knowing what the percentage error is for any baud rate that is not mentioned in the tables in the documentation.

Currently I am using 2048000 baud and this appears to work. 3MBaud did not work (ended up being 3072000 in the micro/clock combination I am using).

I want to be able to understand the baud rate calculation within the CYBT 343026 so that if I need to use another baud rate I can understand the percentage error.

Thanks

Nigel

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