Electronic – c18 assembly inside function problem. unidentified label (bit names)

assemblycpic

Here is the data_write function I'm looking at. I've been told that this method (from the textbook) is not good and I should be using the C method (that is currently commented out). When the Cbits method is used, any arguments after the _asm/_endasm the compiler doesn't recognize the bit names (they don't turn green).

If I use only the assembly method, I get a string of errors [1111] about the undefined label (WR, GIE, EECON1, etc.) inside this function. Do I have to somehow re-define the ADC.h inside the function? Basically, all of the register names (EECON1, etc) and bit names (WR, WREN, etc.) are not recognized inside the function "data_write" if they are inside the assembly tags (_asm/_endasm). If I use the Cbits.BIT method, I get a generic syntax error and the bits following _endasm are not identified (turn green).

#include <stdio.h>
#include <stdlib.h>
#include <p18f452.h>
#include <delays.h>
#include <adc.h>

int result;                         // used in ADC result handling
int write_point=0x64;               // used in data_write function. initial=d100

void data_write (int write_point, int result);   // declare prototype

void main(void)  // <==should this be 'int main (void)' b/c i'm passing result to another function ?
{
    while (1) {
    // sensor 1 configured to port AN0
        OpenADC(ADC_FOSC_8 & ADC_RIGHT_JUST & ADC_5ANA_0REF, ADC_CH0 & ADC_INT_OFF);
                            //configures ADC for port AN0 = sensor 1 input
            ConvertADC();               // initiate conversion of sensor1 @ AN0
            while(BusyADC());           // waiting to complete conversion
            result=ReadADC();           // read the result of sensor1 @ AN0
            data_write(result, write_point);
        CloseADC();
                    }
        }

void data_write (int write_point, int result) {

/*        EECON1bits.EEPGD = 0       // points to data memory
         EECON1bits.CFGS = 0        // access data eeprom
         EECON1bits.WREN = 1        // enable write to data eeprom
         INTCONbits.GIE=0           // disable interrupt
** if I substitute this method of bit control, this 2nd portion belongs after 
 * the asm arguments, but the bits (WR, GIE, WREN) will not be identified
 * either an I get a syntax error. (of course commenting out the bcf/bsf statements)
        EECON1bits.WR = 1       // enable bit to start the write operation
        INTCONbits.GIE = 1      // re-enable interrupt
        EECON1bits.WREN = 0    // restores the write command to =disabled */

_asm
 movlw  write_point        // starting data memory address = data_adr
 movwf  EEADR,A
 movlw  result              // gets data stored in "result" variable
 movwf  EEDATA,A            // places data into data memory holder
 bcf    EECON1,EEPGD,A      // points to data memory
 bcf    EECON1,CFGS,A       // access data eeprom
 bsf    EECON1,WREN,A       // enable write to data EEPROM
 bcf    INTCON,GIE,A         // disable interrupt
 movlw  0x55                // start flash erase sequence
 movwf  EECON2,A
 movlw  0xAA
 movwf  EECON2,A            // end flash erase sequence
 bsf    EECONN1,WR,A        // enable bit to start the write operation
 bsf    INTCON,GIE,A        // re-enable interrupt
 bcf    EECON1,WREN         // restores the write command to =disabled
 _endasm



 write_point = write_point+2;  // increment address by 2
 if (write_point >= 0xC6)      // if address >= d'198
     write_point = 0x64;       // resets starting point to d'100

}

Best Answer

For the commented out C part, you don't appear to have have any ending semicolons (e.g. first line should be EECON1bits.EEPGD = 0;) , so the compiler certainly won't like that.

For the inline assembly, IIRC the register names hould b e usable, but I think you have to specify operands fully (e.g. instead of movwf EECON2,A you do movwf EECON2,0)
It's possible the bit names must be specified by number instead of name too, for example instead of bcf EECON1,EEPGD,A you do bcf EECON1, 7, 0 (EEPGD is bit 7 of EECON1) The A at the end is not right anyway, this should be 1 or 0 (or W or F in MPASM)
It's been a while since I used the inline assembly for anything like this so memory is fuzzy, but try it and let us know how it goes.

Related Solutions

Electronic – c18 coding advice / braces error / function declaration help

All of the other answers have good points, and point out other problems, but the specific reason you're getting the error old style function declarations not supported is because your data_write function declaration is missing the types. It needs to be changed from

void data_write (data_adr, result)

void data_write (int data_adr, int result)

Electronic – Problem with transmitting data from PIC18F45K20 (C18) to MCP23017

The problems had been solved. The source of this problem is that there were acknowledge bits in the wcode. It is not necessary for the master device to send an acknowledge bit to the slave device during the write operation. In fact, the master device should wait for the acknowledge bit from the slave device.

Below is the code for testing the I2C protocol of the PIC18F45K20 with MCP23017.

#include <stdio.h>
#include <stdlib.h>
#include <delays.h>
#include <i2c.h>
#include <p18f45k20.h>
#include <sw_i2c.h>

#define MCP_IODIR_A 0x00
#define MCP_IPOL_A 0x02
#define MCP_OLAT_A 0x14
#define MCP_GPIO_A 0x12
#define MCP_IOCON_A 0x0A
#define MCP_GPINTEN_A 0x04

/*
* 
*/
//----------------------------Global variable----------------------------


// PIC18F45K20 Configuration Bit Settings

// CONFIG1H
#pragma config FOSC = INTIO67   // Oscillator Selection bits (Internal oscillator block, port function on RA6 and RA7)
#pragma config FCMEN = OFF      // Fail-Safe Clock Monitor Enable bit (Fail-Safe Clock Monitor disabled)
#pragma config IESO = OFF       // Internal/External Oscillator Switchover bit (Oscillator Switchover mode disabled)

// CONFIG2L
#pragma config PWRT = OFF       // Power-up Timer Enable bit (PWRT disabled)
#pragma config BOREN = SBORDIS  // Brown-out Reset Enable bits (Brown-out Reset enabled in hardware only (SBOREN is disabled))
#pragma config BORV = 30        // Brown Out Reset Voltage bits (VBOR set to 3.0 V nominal)

// CONFIG2H
#pragma config WDTEN = OFF      // Watchdog Timer Enable bit (WDT is controlled by SWDTEN bit of the WDTCON register)
#pragma config WDTPS = 32768    // Watchdog Timer Postscale Select bits (1:32768)

// CONFIG3H
#pragma config CCP2MX = PORTC   // CCP2 MUX bit (CCP2 input/output is multiplexed with RC1)
#pragma config PBADEN = ON      // PORTB A/D Enable bit (PORTB<4:0> pins are configured as analog input channels on Reset)
#pragma config LPT1OSC = OFF    // Low-Power Timer1 Oscillator Enable bit  (Timer1 configured for higher power operation)
#pragma config HFOFST = ON      // HFINTOSC Fast Start-up (HFINTOSC starts clocking the CPU without waiting for the oscillator to stablize.)
#pragma config MCLRE = OFF      // MCLR Pin Enable bit (RE3 input pin enabled; MCLR disabled)

// CONFIG4L
#pragma config STVREN = ON      // Stack Full/Underflow Reset Enable bit (Stack full/underflow will cause Reset)
#pragma config LVP = OFF        // Single-Supply ICSP Enable bit (Single-Supply ICSP disabled)
#pragma config XINST = OFF      // Extended Instruction Set Enable bit (Instruction set extension and Indexed Addressing mode disabled (Legacy mode))

// CONFIG5L
#pragma config CP0 = OFF        // Code Protection Block 0 (Block 0 (000800-001FFFh) not code-protected)
#pragma config CP1 = OFF        // Code Protection Block 1 (Block 1 (002000-003FFFh) not code-protected)
#pragma config CP2 = OFF        // Code Protection Block 2 (Block 2 (004000-005FFFh) not code-protected)
#pragma config CP3 = OFF        // Code Protection Block 3 (Block 3 (006000-007FFFh) not code-protected)

// CONFIG5H
#pragma config CPB = OFF        // Boot Block Code Protection bit (Boot block (000000-0007FFh) not code-protected)
#pragma config CPD = OFF        // Data EEPROM Code Protection bit (Data EEPROM not code-protected)

// CONFIG6L
#pragma config WRT0 = OFF       // Write Protection Block 0 (Block 0 (000800-001FFFh) not write-protected)
#pragma config WRT1 = OFF       // Write Protection Block 1 (Block 1 (002000-003FFFh) not write-protected)
#pragma config WRT2 = OFF       // Write Protection Block 2 (Block 2 (004000-005FFFh) not write-protected)
#pragma config WRT3 = OFF       // Write Protection Block 3 (Block 3 (006000-007FFFh) not write-protected)

// CONFIG6H
#pragma config WRTC = OFF       // Configuration Register Write Protection bit (Configuration registers (300000-3000FFh) not write-protected)
#pragma config WRTB = OFF       // Boot Block Write Protection bit (Boot Block (000000-0007FFh) not write-protected)
#pragma config WRTD = OFF       // Data EEPROM Write Protection bit (Data EEPROM not write-protected)

// CONFIG7L
#pragma config EBTR0 = OFF      // Table Read Protection Block 0 (Block 0(000800-001FFFh) not protected from table reads executed in other blocks)
#pragma config EBTR1 = OFF      // Table Read Protection Block 1 (Block 1 (002000-003FFFh) not protected from table reads executed in other blocks)
#pragma config EBTR2 = OFF      // Table Read Protection Block 2 (Block 2 (004000-005FFFh) not protected from table reads executed in other blocks)
#pragma config EBTR3 = OFF      // Table Read Protection Block 3 (Block 3 (006000-007FFFh) not protected from table reads executed in other blocks)

// CONFIG7H
#pragma config EBTRB = OFF      // Boot Block Table Read Protection bit (Boot Block (000000-0007FFh) not protected from table reads executed in other blocks)

void init_I2C()
{
    DDRCbits.RC3 = 1; //Configure SCL as input
    DDRCbits.RC4 = 1; //Configure SDA as input

    // SSPSTAT Configuration (0x80)
    SSPSTATbits.SMP = 1;    //Slew rate control disabled
    SSPSTATbits.CKE = 0;    //SMBus disabled
    SSPSTATbits.D_A = 0;    //Reserved in master mode
    SSPSTATbits.P = 0;      //Stop bit was not detected last
    SSPSTATbits.S = 0;      //Start bit was not detected last
    SSPSTATbits.R_W = 0; 
    SSPSTATbits.UA = 0;     //Address doesnot need to be updated
    SSPSTATbits.BF = 0; 

    // SSPCON1 Configuration (0x28)
    SSPCON1bits.WCOL = 0;
    SSPCON1bits.SSPOV = 0;
    SSPCON1bits.SSPEN = 1;  //Serial port enabled
    SSPCON1bits.CKP = 0;    //Holds clock low
    SSPCON1bits.SSPM3 = 1;  //1000 = I2C Master mode
    SSPCON1bits.SSPM2 = 0;  //BitRate = FOSC/(4*(SPPADD+1))
    SSPCON1bits.SSPM1 = 0; 
    SSPCON1bits.SSPM0 = 0;                       

    // SSPADD Configuration
    SSPADD = 0x27;  //should be 0x27 for 100kHz
                    //SSPADD = [(FOSC/BitRate)/4]-1

    // SSPCON2 Configuration (0x00)
    SSPCON2bits.GCEN = 0;       //General call address disabled
    SSPCON2bits.ACKSTAT = 0;    //Acknowledge was received from slave
    SSPCON2bits.ACKDT = 0;      //Acknowledge
    SSPCON2bits.ACKEN = 0;      //Acknowledge sequence idle
    SSPCON2bits.RCEN = 0;       //Receive idle
    SSPCON2bits.PEN = 0;        //Stop condition idle
    SSPCON2bits.RSEN = 0;       //Repeated start condition idle
    SSPCON2bits.SEN = 0;
}

void MCP_write()
{
     WriteI2C(0x40);
}

void MCP_read()
{
     WriteI2C(0x41);
}

void MCP_addr()
{
     StartI2C();
     MCP_write();
}

void init_MCP()
{
     //IODIR A configuration
     MCP_addr();
     WriteI2C(MCP_IODIR_A);
     WriteI2C(0x00);
     StopI2C();

     //IPOL A configuration
     MCP_addr();
     WriteI2C(MCP_IPOL_A);
     WriteI2C(0x00);
     StopI2C();

     //OLAT A configuration
     MCP_addr();
     WriteI2C(MCP_OLAT_A);
     WriteI2C(0xFF);
     StopI2C();

     //IOCON A configuration
     MCP_addr();
     WriteI2C(MCP_IOCON_A);
     WriteI2C(0x00);
     StopI2C();

     //GPINTEN A configuration
     MCP_addr();
     WriteI2C(MCP_GPINTEN_A);
     WriteI2C(0x00);
     StopI2C();
} 


//----------------------------Main program----------------------------
void main(void)
{
     OSCCON = 0x70;      //Set internal oscillation to 16 MHz
     TRISD=0;
     init_I2C();         //I2C initialization
     init_MCP();         //MCP23017 initialization

     while(1)
     {
         MCP_addr();
         WriteI2C(MCP_GPIO_A);
         WriteI2C(0x11);
         StopI2C();
     }
}

Best Answer

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Electronic – c18 coding advice / braces error / function declaration help

Electronic – Problem with transmitting data from PIC18F45K20 (C18) to MCP23017

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