Re: [Xenomai-core] 16550A driver and Moxa card / solved

[Jan Kiszka <jan.kiszka@domain.hid>]

[-- Attachment #1: Type: text/plain, Size: 1061 bytes --]

Maksym Veremeyenko wrote:
> Jan Kiszka пишет:
>>> moxa: 912.600/115.200 = 8
>>> xeno: = 7
>>
>> Yeah, hard arguments. This really cries for a moxa tweak. (The
>> alternative would be to pass an artificially increased baud_base - but
>> that would be _really_ ugly and we could also ask the user for the
>> divider directly...)
> 
> As i correctly understand mxser use formula:
>       +-
>       | base/baud, baud <> 134
> div = |
>       | 2*base/(2*base + 1), baud == 134
>       +-
> 
> Jan's driver use:
> 
> div = (base + baud/2)/baud
> 
> What is actual
> 
> div = base/baud + 0.5
> 
> That seems more correct for rounding....
> 
> 
> In additional:
> 1. You should use 921600 value instead of 912.600.

(921600 + (115200 div 2)) div 115200 = 8

So back to square #1: misconfiguration? David, please check with the
correct baud base again if you still see relevant divider variations.

> 2. Interface is asynchronous and (IMHO) data could be transfered in a
> range of frequencies (BAUD +/- RANGE%)
> 

Jan


[-- Attachment #2: OpenPGP digital signature --]
[-- Type: application/pgp-signature, Size: 250 bytes --]