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+--- Thread: UARTBR - wrong baud rate calculation formula [solved] (/showthread.php?tid=78)
UARTBR - wrong baud rate calculation formula [solved] - yuters - 2011-04-24
Hi,
As I see in PIC24FJ128GA110 datasheet (page 182) the UART baud rate with "BRGH = 1" calculated by following formula:
UARTBR = (FCY/(4*Baud Rate) -1)
but in BL code I see following:
.ifdef USE_BRGH
.equ UARTBR, ( (((FCY / BAUDRATE) / 2) - 1) / 2 )
.endif
The datasheet formula checked in my applications and work fine on 115200 bps baud rate.
So it's looking like there must be:
.equ UARTBR, ((FCY / (4*BAUDRATE)) - 1)
Is it try?
Regards.
Yuters
RE: UARTBR - wrong baud rate calculation formula - Mikael Gustavsson - 2011-04-24
Hi,
My version does rounding to achieve better results.
Try it yourself to see how it works.
Thanks,
Mikael