Lpc2000

Robert Adsett wrote:

>At 04:47 PM 4/28/2006 -0400, Tom Walsh wrote:
>  
>
>>Robert Adsett wrote:
>>    
>>
>>>Quoting bacalaoencebollao <bacalaoencebollao@...>:
>>>      
>>>
>>>>I have a problem with my programme, i want to make my UART work, but
>>>>without the FIFOs, is there anyway to get a receive interrupt when
>>>>only one character has been recieved, or do I have to wait for the
>>>>FIFO to be full?
>>>>
>>>>
>>>>        
>>>>
>>>The FIFO must be turned on.
>>>
>>>However, you will recieve an interrupt on a single character.  It will 
>>>      
>>>
>>just be
>>    
>>
>>>delayed (by 1.5 character time IIRC).  That allows the buffer to fill for a
>>>stream of characters but interrupt on pauses in the stream if there are
>>>characters waiting in the FIFO.
>>>
>>>
>>>
>>>      
>>>
>>I run interrupt driven I/O on UART0 without the FIFO turned on...  Seems
>>to work fine for me on the LPC2138 and LPC2106.
>>    
>>
>
>It's a nasty little bug Tom, I was running w/o the FIFOs on and ran into a 
>problem that I eventually 'fixed' by only reading the IIR once per 
>interrupt.  Before that under an echo load the serial interrupts would 
>occasionally stop.  (My test was a simple echo test and it would take 
>several hours to fail at full load)  Note that these tests were on a 2106.
>
>  
>
Robert, thanks for the info on this.  I'll have to do some more testing 
on the LPC2000 uarts.  Most stringent testing has been on the SPI + 
MAX3100 uarts.

TomW

-- 
Tom Walsh - WN3L - Embedded Systems Consultant
http://openhardware.net, http://cyberiansoftware.com
"Windows? No thanks, I have work to do..."
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