Ilia Gildin
Junior Member level 3
Hi I wrote the following code to interface thrugh rs-232
and as you can guess its not working.
I use Visual Studio to transmit and receive the data the Visual Studio works fine as I could link the Tx and Rx legs of rs-232 connector I can not do that with a microchip because the other end of my cable is USB. I use PICDEM2 black board.
sincerely yours
Gildin Ilia
Code:
;******************************************************************************
; *
; This file is a basic code template for code generation on the *
; PIC18F46K22. This file contains the basic code building blocks to build *
; upon. *
; *
; Refer to the MPASM User's Guide for additional information on features *
; of the assembler. *
; *
; Refer to the respective data sheet for additional information on the *
; instruction set. *
; *
;******************************************************************************
; *
; Filename: xxx.asm *
; Date: *
; File Version: *
; Author: *
; Company: *
; *
;******************************************************************************
; *
; Files Required: *
; *
;******************************************************************************
; *
; Notes: *
; *
;******************************************************************************
; *
; Revision History: *
; *
;******************************************************************************
;------------------------------------------------------------------------------
; PROCESSOR DECLARATION
;------------------------------------------------------------------------------
LIST P=PIC18F46K22 ; list directive to define processor
#INCLUDE <P18F46K22.INC> ; processor specific variable definitions
;------------------------------------------------------------------------------
;
; CONFIGURATION WORD SETUP
;
; The 'CONFIG' directive is used to embed the configuration word within the
; .asm file. The lables following the directive are located in the respective
; .inc file. See the data sheet for additional information on configuration
; word settings.
;
;------------------------------------------------------------------------------
;Setup CONFIG11H
CONFIG FOSC = INTIO67, PLLCFG = OFF, PRICLKEN = OFF, FCMEN = OFF, IESO = OFF
;Setup CONFIG2L
CONFIG PWRTEN = OFF, BOREN = OFF, BORV = 190
;Setup CONFIG2H
CONFIG WDTEN = OFF, WDTPS = 1
;Setup CONFIG3H
CONFIG MCLRE = EXTMCLR, CCP2MX = PORTC1, CCP3MX = PORTE0, HFOFST = OFF, T3CMX = PORTB5, P2BMX = PORTC0
;Setup CONFIG4L
CONFIG STVREN = OFF, LVP = OFF, XINST = OFF
;Setup CONFIG5L
CONFIG CP0 = OFF, CP1 = OFF, CP2=OFF, CP3=OFF
;Setup CONFIG5H
CONFIG CPB = OFF, CPD = OFF
;Setup CONFIG6L
CONFIG WRT0 = OFF, WRT1 = OFF, WRT2 = OFF, WRT3 = OFF
;Setup CONFIG6H
CONFIG WRTB = OFF, WRTC = OFF, WRTD = OFF
;Setup CONFIG7L
CONFIG EBTR0 = OFF, EBTR1 = OFF, EBTR2 = OFF, EBTR3 = OFF
;Setup CONFIG7H
CONFIG EBTRB = OFF
;------------------------------------------------------------------------------
;
; VARIABLE DEFINITIONS
;
; Refer to datasheet for available data memory (RAM) organization
;
;------------------------------------------------------------------------------
CBLOCK 0x60 ; Sample GPR variable register allocations
MYVAR1 ; user variable at address 0x60
MYVAR2 ; user variable at address 0x61
MYVAR3 ; user variable at address 0x62
ENDC
W_TEMP EQU 0x000 ; w register for context saving (ACCESS)
STATUS_TEMP EQU 0x001 ; status used for context saving
BSR_TEMP EQU 0x002 ; bank select used for ISR context saving
;------------------------------------------------------------------------------
; EEPROM INITIALIZATION
;
; The 18F46K22 has 256 bytes of non-volatile EEPROM starting at 0xF00000
;
;------------------------------------------------------------------------------
DATAEE ORG 0xF00000 ; Starting address for EEPROM for 18F46K22
DE "MCHP" ; Place 'M' 'C' 'H' 'P' at address 0,1,2,3
;------------------------------------------------------------------------------
; RESET VECTOR
;------------------------------------------------------------------------------
RES_VECT ORG 0x0000 ; processor reset vector
GOTO START ; go to beginning of program
;------------------------------------------------------------------------------
; HIGH PRIORITY INTERRUPT VECTOR
;------------------------------------------------------------------------------
ISRH ORG 0x0008
; Run the High Priority Interrupt Service Routine
GOTO HIGH_ISR
;------------------------------------------------------------------------------
; LOW PRIORITY INTERRUPT VECTOR
;------------------------------------------------------------------------------
ISRL ORG 0x0018
; Run the High Priority Interrupt Service Routine
GOTO LOW_ISR
;------------------------------------------------------------------------------
; HIGH PRIORITY INTERRUPT SERVICE ROUTINE
;------------------------------------------------------------------------------
HIGH_ISR
; Insert High Priority ISR Here
rs232
btfss TXSTA1,TRMT ;CHECK IF xmit buffer empty
bra rs232 ;no, wait
movff RCREG1,TXREG1 ;move the data in temp2 register to TXREG1 rs-232 transmition starts from this point
;RETFIE FAST
;------------------------------------------------------------------------------
; LOW PRIORITY INTERRUPT SERVICE ROUTINE
;------------------------------------------------------------------------------
LOW_ISR
; Context Saving for Low ISR
MOVWF W_TEMP ; save W register
MOVFF STATUS, STATUS_TEMP ; save status register
MOVFF BSR, BSR_TEMP ; save bankselect register
; Insert Low Priority ISR Here
; Context Saving for Low ISR
MOVFF BSR_TEMP, BSR ; restore bankselect register
MOVF W_TEMP, W ; restore W register
MOVFF STATUS_TEMP, STATUS ; restore status register
RETFIE
;------------------------------------------------------------------------------
; MAIN PROGRAM
;------------------------------------------------------------------------------
;for rs 232 boud rate 9600 need 16MHz
START
clrf ANSELC ;analog module off
movlw B'11000000' ;load to W the binary number of '11000000'
movwf TRISC ;TX and RX pins as input as required for rs 232
movlw B'01110110' ;load to W the binary number of '01110110'
movwf OSCCON ;configure 16 MHz with stable HFIOST
bsf BAUDCON1,BRG16 ;enable 16 bit baud rate
bsf TXSTA1,BRGH ;high speed baud rate as we only will use 9600
;-----------------------------------------------------------------------------
; Fosc
;Baud_Rate=---------------------------------------------------------------- from ERRATA
; [4([SPBRGH1:SPBRG1]+1)]
;-----------------------------------------------------------------------------
movlw 0X0 ;load 0X1 to W
movwf SPBRGH1 ;move the data from Wreg to SPBRGH FOR DESIRED BOUD RATE OF 9600
movlw b'11001111' ;move the binary number of 10011111 to Wreg
movwf SPBRG1 ;move W TO SPBRG1 FOR DESIRED BOUD RATE OF 19200
bcf TXSTA1,SYNC ;rs-232 is asynchronous communication
bcf TXSTA1,TX9
bsf RCSTA1,SPEN ;serial port enabled
bsf TXSTA1,TXEN ;WE WRITE DATA ON TXREG1 AND THE TRANSMISION STARTS AUTOMATICLY
bsf RCSTA1,CREN ;RECIEVE DATA FROM COMPUTER TO RCREG1
bcf RCSTA1,RX9
bcf RCON,IPEN ;disable low priority interrupts
bsf INTCON,GIE_GIEH ;enable all unmasked interrupts
bsf INTCON,PEIE_GIEL ;enable all unmasked peripheral interrupts
bsf PIE1,RC1IE ;interrupt of rs-232 recieved
r
bra r
endI use Visual Studio to transmit and receive the data the Visual Studio works fine as I could link the Tx and Rx legs of rs-232 connector I can not do that with a microchip because the other end of my cable is USB. I use PICDEM2 black board.
sincerely yours
Gildin Ilia
