AM6548: Using the Main UARTs

John Hoffman

Part Number: AM6548

I am using the AM65xx IDK and EVM evaluation module.

I am using the rtos_template_app_am65xx_a53 example project.

I am trying to modify the example UART driver code so that I can utilize the Main UART 1 for testing.

So far, the only code that I have modified is in the board_lld_init.c file.

//UART_stdioInit(BOARD_UART0_INSTANCE);//Main UART 0
UART_stdioInit(BOARD_UART1_INSTANCE);//Main UART 1

I am monitoring the 4 input pins on the Multiplexer chip (U42, pins 4, 7, 9, 12) in order to see the signal coming out from the UART,

but I am not seeing any activity.

Do you know which input pin the Main UART 1 is mapped to?

Do you know what other code I need to modify to activate Main UART 1?

Thanks

0 ANUBHAV AKASH over 5 years ago

Hi,

In AM65x, UART1 is connected through io-expander.

Therefore, for enabling UART_1, you have to enable the MAIN_UART1_SEL, which is connected to I2c IO Expander - PORT1-PIN5.

for reference, you can take a look at "BoardDiag_enableUART1Sel()" in the below path:

pdk_am65xx_XX_XX_XX_XX\packages\ti\board\diag\uart\src\uart_diag.c.

0 John Hoffman over 5 years ago

Thanks for that reference.

The purpose of the I2C IO Expander is to direct (multiplex) the Main UART 1 signal either to the FT4232 or to the Application connector, correct?

So, shouldn't the Main UART 1 Tx signal always be available to 1 of the 4 inputs of the multiplexer (U42)?

0 ANUBHAV AKASH over 5 years ago in reply to John Hoffman

can you please tell which revision of hardware you are having and which version of processor_rtos_package you are using.

0 John Hoffman over 5 years ago

I am using AM654x EVM PROCESSOR, PCB REV:E4, ASSM REV:1.0

pdk_am65xx_07_01_00_55

processor_sdk_rtos_am65xx_07_01_00_14

+1 ANUBHAV AKASH over 5 years ago in reply to John Hoffman

Thanks for the reply. U42 is not connected to UART lines. It is connected to JTAG clock buffers. You can check U26 for UART1 lines

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