Post by thread:[PIC] 877a+hardware uart+software uart = ARGHHHH

Hello ive a project in wich i need to use the hardware uart of the 877a and a software uart, the hardware uart work well, the software gives sometimes random caracteres :(, the strange thing is if i put a very long pause between transmiting caracters using the software uart it doesnt send garbage caracters ..... this is the routines have been using clockrate equ .10000000 ; define clock rate (XTAL frequency) here baudrate_simulada equ .19200 ; define baud rate here fclk equ clockrate/4 baudconst equ ((fclk/baudrate_simulada)/3 - 2) ;2 ;fim das definicoes ; ; Serial Transmit Routine ; transmit movwf tx_reg bcf _tx ;send start bit movlw baudconst movwf delay movlw .9 movwf count txbaudwait decfsz delay, F goto txbaudwait movlw baudconst movwf delay decfsz count, F goto SendNextBit movlw .9 movwf count bsf _tx ;send stop bit return SendNextBit rrf tx_reg, F btfss STATUS,C goto Setlo bsf _tx goto txbaudwait Setlo bcf _tx goto txbaudwait