termios with high baud rate...

[Charles Steaderman]

I got an error posting my original reply. This one is plain text only.

- Charlie

Charles Steaderman wrote:

>
>
> Stan wrote:
>
>>----- Original Message ----- 
>>From: "Charles Steaderman" <charlies at poliac.com>
>>To: "Stan" <zylog at club-internet.fr>
>>Cc: "rtems-users" <rtems-users at rtems.com>
>>Sent: Thursday, January 15, 2004 9:30 PM
>>Subject: Re: termios with high baud rate...
>>
>>
>>  
>>
>>>I have a custom 5206e board working with 60096 baud with interrupt based 
>>>termios, although the data from the sending device is not entirely 
>>>continuous. I will see if I can find a way to quickly modify my 
>>>application to test at 115200. How are you sending a continuous stream? 
>>>    
>>>
>>
>>I send a text file with one terminal (PC).
>>
>>
>>  
>>
>>>I am sure that hardware handshaking will be necessary. Is that OK for 
>>>your application?
>>>
>>>- Charlie
>>>    
>>>
>>
>>My application is a simple buffer.
>>It must to work without hardware handshaking ( at least at 57600 ).
>>The 5206e ColdFire is fast ( 50 Mhz ),  it should be fast enough
>>for do it.
>>  
>>
> The bigger problem is not the speed of the processor, but the number 
> of buffer registers in the serial port controller. I believe that the 
> ColdFire only has a 4 byte serial port buffer. If you are running one 
> task and polling the port, I could see 57600 working. If you are 
> running interrupt driven and you have other things going on, > 57600 
> without hardware handshaking will probably be a problem. The standard 
> PC UART (16550) has 14/16 byte buffers to handle higher baud rates 
> better without hardware handshaking. Do you intend to use interrupt 
> driven or polling for your termios/serial port configuration or does 
> it not matter?
>
> - Charlie
>
>>Stan.
>>
>>  
>>
>
>-- 
>Charlie Steaderman
>charlies at poliac.com
>VP Engineering
>Poliac Research Corporation
>Phone: 952.707.6245
>Cel: 612.242.6364
>

-- 
Charlie Steaderman
charlies at poliac.com
VP Engineering
Poliac Research Corporation
Phone: 952.707.6245
Cel: 612.242.6364