ja asembler smatram teskim gubljenjem vremena (tako da sam nesvesno izignorisao taj deo u originalnom postu) no .. pogledaj npr:
ne znam da li mu taj primer koristi 16F876 ili 16F628. Nigelovi primeri su super za pocetnike koji zele da se gube vreme na asm
Code:
;*******************************************************************
; Function: Sends alive message, then echoes characters at 9600 bps
; Processor: PIC16F628 at 4 MHz using internal RC oscillator
; Hardware: Testboard K4
; Filename: 628uart.asm
; Author: Lars Petersen,
[email protected]
; Website: www.qsl.net/oz1bxm/PIC/pic.htm
; Credit: Tony Nixon's test program at
; www.piclist.com/techref/microchip/16f877/setup.htm
;*******************************************************************
LIST P=16F628, R=DEC ; Use the PIC16F628 and decimal system
#include "P16F628.INC" ; Include header file
__config _INTRC_OSC_NOCLKOUT & _LVP_OFF & _WDT_OFF & _PWRTE_ON & _BODEN_ON
CBLOCK 0x20 ; Declare variable addresses starting at 0x20
dataL
ENDC
ORG 0x000 ; Program starts at 0x000
;
; --------------------------------
; SET ANALOG/DIGITAL INPUTS PORT A
; --------------------------------
;
movlw 7
movwf CMCON ; CMCON=7 set comperators off
;
; ----------------
; INITIALIZE PORTS
; ----------------
;
movlw b'00000000' ; set up portA
movwf PORTA
movlw b'00000100' ; RB2(TX)=1 others are 0
movwf PORTB
bsf STATUS,RP0 ; RAM PAGE 1
movlw 0xFF
movwf TRISA ; portA all pins input
movlw b'11110010' ; RB7-RB4 and RB1(RX)=input, others output
movwf TRISB
; ------------------------------------
; SET BAUD RATE TO COMMUNICATE WITH PC
; ------------------------------------
; Boot Baud Rate = 9600, No Parity, 1 Stop Bit
;
movlw 0x19 ; 0x19=9600 bps (0x0C=19200 bps)
movwf SPBRG
movlw b'00100100' ; brgh = high (2)
movwf TXSTA ; enable Async Transmission, set brgh
bcf STATUS,RP0 ; RAM PAGE 0
movlw b'10010000' ; enable Async Reception
movwf RCSTA
;
; ------------------------------------
; PROVIDE A SETTLING TIME FOR START UP
; ------------------------------------
;
clrf dataL
settle decfsz dataL,F
goto settle
movf RCREG,W
movf RCREG,W
movf RCREG,W ; flush receive buffer
;
; ---------
; MAIN LOOP
; ---------
;
call message ; send "16F628 alive"
loop call receive ; wait for a char
call send ; send the char
goto loop
;
; -------------------------------------------
; RECEIVE CHARACTER FROM RS232 AND STORE IN W
; -------------------------------------------
; This routine does not return until a character is received.
;
receive btfss PIR1,RCIF ; (5) check for received data
goto receive
movf RCREG,W ; save received data in W
return
;
; -------------------------------------------------------------
; SEND CHARACTER IN W VIA RS232 AND WAIT UNTIL FINISHED SENDING
; -------------------------------------------------------------
;
send movwf TXREG ; send data in W
TransWt bsf STATUS,RP0 ; RAM PAGE 1
WtHere btfss TXSTA,TRMT ; (1) transmission is complete if hi
goto WtHere
bcf STATUS,RP0 ; RAM PAGE 0
return
;
; -------
; MESSAGE
; -------
;
message movlw '1'
call send
movlw '6'
call send
movlw 'F'
call send
movlw '6'
call send
movlw '2'
call send
movlw '8'
call send
movlw ' '
call send
movlw 'a'
call send
movlw 'l'
call send
movlw 'i'
call send
movlw 'v'
call send
movlw 'e'
call send
movlw 0x0D ; CR
call send
movlw 0x0A ; LF
call send
return
END