> -----Original Message-----
> From: l...
> [mailto:l...]On Behalf Of zied130187
> Sent: Thursday, December 02, 2010 10:23 AM
> To: l...
> Subject: [lpc2000] Re: problem UART - LPC2129 - kit olimex
>
> hello, thank you for your response
> when i use this instruction
> U0THR = character_value(dat);
> in IAR you can see the value of any register in the window register
> without use any function
> and the value of U0THR ahter my instruction is 0xFF and not 0x41
>
> i don't understand why the register don't change in value 0x41

Because it is a write only register. You cannot read the value back
via any means. This includes not being able to read it via the IAR
register window. It is not possible.

If you do read it, you are reading U0RDR, which is the recieve data
register (as U0THR, and U0RDR share the same address). So you will
get data recieved by the UART, not what you sent.

Mike

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