I meet a confusing problem... I have to use UART & IIC communication simultaneously. The internal SCL generator is selected for the I2C clock. data rate is 100Kbit/sec at fosc=12MHz. Baudrate generator is selected for UART clock. 9600bps is set. The problem is that IIC works incorrectly if baudrate generator for UART is set enable. It always halts after transmitting/receiving one or two bytes of data and can't finish whole communication properly. How to solve this problem ? Thanks...