Lpc2000

Hello,

There is a simple tip to generate the 13-bit break without having to implement 
external glue logic. The LIN bus operates at know (an relatively low) 
bitrates.

The idea is to change the value of the prescaler that defines the baudrate in 
the UART. You can calculate a "virtual" baudrate that make an eight-bit long 
0x00 byte as long as 13-bits at the nominal LIN bus bitrate. 

After the break has been sent, you can switch back to the normal prescaler 
value for the LIN bus speed and go on with the rest of the frame. I Haven't 
checked if the prescaler settings possible with an LPC2129 allow this with 
enough accuracy to mach the constraints of the LIN spec, but I think it 
should work.

This  was used in the very first implementations of the LIN protocol, when 
LIN-compliant UARTs (like in the 16F690) were not yet available. I Remember 
examples in old appnotes from Infineon on their C167 controller. Probably 
this is still available on their website.

Hope this can save extra hardware ... which represents money !!

Regards

"Duke"

Le Mercredi 29 Mars 2006 23:20, Tennessee Carmel-Veilleux a écrit :

>  On Mar 29, 2006, at 8:37 AM, alberto wrote:
>  > Hi guys,
>  >  Has someone developed a Local interconect network on LPC2129?
>  >  There is somewhere a simple LIN stack?
>
>  The LPC2129 is not able to do LIN with its UART unless you use other
>  pins and glue logic to be able to generate the BREAK signal (13 bits)
>  and implement an auto-baud detect. I suggest you program a PIC16F690
>  with a simple SPI or I2C LIN stack that will interface with your LPC.
>  The PIC16F690 contains all the necessary peripherals and is a very
>  small footprint.
>
>  Best Regards,
>
>  Tennessee Carmel-Veilleux
>
>
>
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