Hi All,

I am new to PIC programming and am trying to get UART working on 18f4455.
Connections seems to be right as char's echo back when i remove the 18f4455
chip and short trx & rcx pins on socket.
However, I am not sure if following program that i am using is right or if
there is some problems with the configs bit settings.

Can someone pls. take a look and help me.


Using 20 Mhz crystal with 18f4455.

Config Bits:
300000h : 0x00
300001h : 0x02        // XT Osc. PLL Enabled.
300002h : 0x3f        // USB Voltage Regulator enabled.
300003h : 0x1f        // WDT Disabled.
300004h : --
300005h : 0x83
300006h : 0x85
300007h : --
300008h : 0x0f
300009h : 0xc0
30000ah : 0x0f
30000bh : 0xe0
30000ch : 0x0f
30000dh : 0x40

Program Source Code:
--------------------

    list p=18f4455  ; set processor type
    list n=0        ; supress page breaks in list file
    include <p18f4455.inc>

;************************************************************
; Reset and Interrupt Vectors

    org 00000h  ; Reset Vector
    goto    Start

    org 00008h  ; Interrupt vector
    retfie

;************************************************************
; Program begins here

    org 00020h  ; Beginning of program EPROM
Start
    clrf    LATB         ; Clear PORTB output latches
    clrf   TRISB         ; Config PORTB as all outputs

    ;Set Trx & Rcx to 1.
    bcf TRISC, 7
    bcf TRISC, 6

    ; Setup Serial Port.
    movlw   81h ; 9600 baud @20MHz.
    movwf   SPBRG

    bcf BAUDCON, BRG16     ; 8-bit Baud Rate Generator.

    bcf TXSTA, TX9     ; 8 bit transmission.
    bsf TXSTA, TXEN       ; Enable transmit.
    bcf TXSTA, SYNC     ; Async. mode.
    bsf TXSTA, BRGH      ; Select high baud rate

    bsf RCSTA, SPEN      ; Enable Serial Port
    bsf RCSTA, CREN      ; Enable continuous reception
    bcf RCSTA, RX9     ; 8-bit Receive.

    bcf PIR1, RCIF       ; Clear RCIF Interrupt Flag
;    bsf PIE1, RCIE      ; Set RCIE Interrupt Enable
;    bsf INTCON, PEIE    ; Enable peripheral interrupts
;    bsf INTCON, GIE     ; Enable global interrupts

;************************************************************
; Main loop

Main
    movlw   'a'
    movwf   TXREG
    nop
    nop
    nop
    nop
    goto    Main    ; loop to self, doing nothing



Thankx,
Jack
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