[CYBT-343026-01] Pin state during reset

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YoJa_3107936
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Hi

Could you tell me the state of the following pins during reset?((Hi-Z state?)

16pin UART_TXD
17pin UART_CTS
18pin UART_RTS
20pin UART_RXD

Thanks

Yang

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1 Solution
SheetalJ
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Hi jiang-y_3107936,

For CYW20706, you dont have to bother about these UART pins during reset. You have to use XRES pin for resetting the device. Otherwise, you have to send an reset command from host to achieve a soft reset if XRES is not connected.

The CTS pin status comes in scenario when you have to recover the board. Following KBA should be helpful: WICED Module Programmer User Guide – KBA225060

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SheetalJ
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Hi jiang-y_3107936,

For CYW20706, you dont have to bother about these UART pins during reset. You have to use XRES pin for resetting the device. Otherwise, you have to send an reset command from host to achieve a soft reset if XRES is not connected.

The CTS pin status comes in scenario when you have to recover the board. Following KBA should be helpful: WICED Module Programmer User Guide – KBA225060

YoJa_3107936
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Hi

>For CYW20706, you dont have to bother about these UART pins during reset.

Could you please tell me why?

* We want to check if there is no problem even if a signal is input to the UART pin during reset,.

We need concrete explanation such as "It is Hi-z, so there is no problem".

Thanks

Yang

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For WICED chips, we provide XRES pin for resetting the device. If you are not using the XRES pin, then you can provide soft reset to the chip, which is done by using commands. CTS is required only when you recover the device. Attached blog post in my previous response might clear things for you.

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YoJa_3107936
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We just want to know the state of the following pins,
when resetting the device(with XRES pin or soft reset)

16pin UART_TXD
17pin UART_CTS
18pin UART_RTS
20pin UART_RXD

Like pre-question, We want to know if there is no problem that a signal is input to the UART pin during reset.

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Reset is the highest priority interrupt. When you are resetting the device, boot code will start executing. Even if you are sending some input to GPIO (UART pins), those values will be neglected and reset will occur. It will not affect the operation even if you send any signal on UART pins during reset.

YoJa_3107936
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Hi

Thank you for your cooperation.

> It will not affect the operation even if you send any signal on UART pins during reset.

According to your description, I think that the state of UART pins is Hi-Z. Is this understanding correct?

If not, please tell me the status of UART pins.

16pin UART_TXD

17pin UART_CTS

18pin UART_RTS

20pin UART_RXD

Thanks

Yang

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yes the pins can be put in hi-z state.

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YoJa_3107936
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I understand that your answer is [UART pins are in hi-z state during reset].

Is it correct?

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YoJa_3107936
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I understand that you mean [UART pins are in hi-z state during reset].

Is it correct?

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yes

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