switching of board rate in PIC microcontrollers

[thunderboympm]

hi,
One of my project i am using PIC microcontroller (PIC18F452). in the particular project i am using two serial communication devices. i am using cd4016 for switching between them. the problem is the two devices are communicating with two different board rate, is there any problems will arise in the communication between the devices and microcontroller, i mean FERR or OERR?

 

[KlausST]

Hi,

What you mean is "baud rate".

The CD4016 will not cause any baud rate problem. But your software needs to handle the different baud rates.

You should switch the CD4016 only when the all communications are idle. Else you have to expect FERR and/or OERR.
..but then just dismiss the received data...

Klaus

 

[spudboy488]

The RX input of the unused communications device should also be pulled to logic high. The is the idle state for the PIC TX line. Leaving it floating or low has caused me problems when switching between different devices. I'm switching on the digital side since I need to route to other uCs as well as RS-232 drivers to external equipment. If you switch on the RS-232 side, it may not make a difference. Just something to keep in mind.