16F648 and 115200 at 4 Mhz doesn't work...

[Darrel Taylor]

While the USART can go that fast at 4mhz, the closest to 115,200 you can get is 125,000, which is an 8.5% error.

If you use a 3.579mhz colorburst crystal. You can get 111,243 baud which is only 2.9% error.

Also there are a couple problems in your code. They may just be typo's, but...

The SERIALBYTE variable is missing. and...
just before JUMP: the "END IF" should be ENDIF.

HTH,

[boban]

Cus Darrel,
OK, thanks for the answer. These typo is OK, I have just copy paste the parts of my code to get the idea to the others, what I am doing )))) So what you wrote is, that it is not possible to use this PIC at 4 Mhz with 115200. So you are suggesting to change tje crystal and to use 3.579 Mhz crystal, and in that case, it should work? I am now wondering, what will happen with PIC basic, because this is I think not supported. In manual for PIC basic is written that only supported values are 4, 8, 20 Mhz. Am I right? If not, what should be the OSC?

[Darrel Taylor]

OSC 3 is for 3.579mhz. (PBP manual page 170)

All the timing (pauses etc.) should work fine.