Hello, This feels like a simple question but I've had very little luck finding any answers. I have an 18F4550 on the PICDEM FSUSB board. It has a 20Mhz crystal. I am trying to send data out over rs232. I have gotten everything working at 9600 baud but this is just barely able to keep up with my data source (clocked in from an FPGA). I have been programming with the hi-tech compiler and MPLAB. Code for the usart: OpenUSART(USART_TX_INT_OFF & USART_RX_INT_OFF & USART_ASYNCH_MODE & USART_EIGHT_BIT & USART_CONT_RX & USART_BRGH_LOW, 78); Header code: #define _XTAL_FREQ 20000000 // (20 MHz crystal on PICDEM FS USB board) #pragma config PLLDIV =3D 5 #pragma config CPUDIV =3D OSC1_PLL2 #pragma config USBDIV =3D 2 #pragma config FOSC =3D HSPLL_HS I would appreciate any help calculating out the numbers for a higher speed. I have been shooting for 115200 with out any luck. I've gone through the datasheet but i'm lost. Thanks in advance. Bill --=20 http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .