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uart tx buf not changed

开发者 https://www.devze.com 2023-01-23 07:34 出处：网络

I am using EWARM IDE from IAR with an Olimex development board for the ARM STR712FR2, and a J-link JTAG debugger provided by IAR. For some reason, I can\'t seem to write to the UART TxBUFR register. I

相关专题：arm

I am using EWARM IDE from IAR with an Olimex development board for the ARM STR712FR2, and a J-link JTAG debugger provided by IAR. For some reason, I can't seem to write to the UART TxBUFR register. I believe I h开发者_如何学Pythonave configured all the clocks and baud rate correctly. The datasheet says that when I write to the TxBUFR register, the UART is supposed to immediately start transmitting. I am running this in debug mode, and when I place a breakpoint right after I set the TxBUFR to a value, the register still shows 0x0000, unchanged.

The register value may not change or it may be write-only, have you checked to see if it is actually transmitting or not?

The UART_CR register resets to 0 which has some fields set to reserved values. Have you configured all the fields in here? ALso, as was mentioned, UART_TxBUFR is a write-only register, so you will not be able to read the value back.