LPC13xx Uart Initialisation

[mikesimmonds]

In the user manual UM10375 (rev 5) section 12.2, it states that ...

Pins: For the LPC1311/13/42/43 parts, the UART pins must be configured in the

IOCONFIG register block (Section 7.4) before the UART clocks can be enabled.

What happens if the clock are enabled first?

(a) non-operation,

(b) unreliable operation,

(c) chip explodes,

(d) other, Please specify!

Cheers, Mike.

[kerryzhou]

Hi Mike,

Thank you for your interest in NXP LPC product, I would like to provide service for you!

At first, we need to know the function of IOCONFIG register.

It configures the pin function, mode, hysteresis, opendrain mode.

What's the pin function?

Take PIO1_7 as an example, this pin have IO function, UART TXD function, CT32B0_MAT1 function.

How did the cpu know the PIO1_7 function? just use this register to configure it.

After reset, the FUNC is 0, it is the IO function.

So, if you don't configure the pin as UART function, even you operate the UART module, the pin can't send the uart data, you can't do the uart communication.

Wish it helps you!

If you still have question, please let me know!

Have a great day,
Jingjing

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