Communication problem in UART

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User11021
Level 1
Level 1
Good After noon every one,

I am working with XMC1100 microcontrller, I have configured UART to USIC0_CH1. I am Sending one command to another controller.
when i do POWER on reset, After that when i send the command 1st time the other controller is get hanged.after resetting that controller then there is no communication problem.

this is happening Afert POWER ON RESET.

can anybody please tell me, what might be the problem...

Best Regards,
Srikanth.
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2 Replies
chismo
Employee
Employee
First like received
Hello Srikanth,

When the XMC device is first powered up, I expect the UART pin to be uninitialized and at its default low level.
The pin will then be initialized and changed to the high level, which is the passive state for the UART protocol.
After the initialization, will the first transmission be able to take place.

In this case, how does the other controller behaves during this time the GPIO of XMC device is being initialized?
Typically to avoid potential problems related to this, the pin is connected to a pull-up resistor.

Regards,
Min Wei
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Not applicable
Are both micros powered by the same rail supply? If the VCC of one micro rises faster than the VCC of the other micro, the micro with the slower VCC can get latched up.
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