cstructheadermicrochippic24

PIC24 setting bits in registers


I am doing some programming for PIC24FJ192GA106 in MPLABX with XC16 compiler using C. I get the following problem during compilation

error: request for member 'UARTEN' in something not a structure or union

the line is question is:

U1MODE.UARTEN = '1';

U1MODE is a structure defined within #include "p24FJ192GA106.h" (header is included within the file) and the certain strcture is as follows

`#define U1MODE U1MODE
extern volatile unsigned int  U1MODE __attribute__((__sfr__));
__extension__ typedef struct tagU1MODEBITS {
  union {
    struct {
      unsigned STSEL:1;
      unsigned PDSEL:2;
      unsigned BRGH:1;
      unsigned RXINV:1;
      unsigned ABAUD:1;
      unsigned LPBACK:1;
      unsigned WAKE:1;
      unsigned UEN:2;
      unsigned :1;
      unsigned RTSMD:1;
      unsigned IREN:1;
      unsigned USIDL:1;
      unsigned :1;
      unsigned UARTEN:1;
    };
    struct {
      unsigned :1;
      unsigned PDSEL0:1;
      unsigned PDSEL1:1;
      unsigned :5;
      unsigned UEN0:1;
      unsigned UEN1:1;
    };
  };
} U1MODEBITS;
extern volatile U1MODEBITS U1MODEbits __attribute__((__sfr__));`

I have also tried

U1MODEbits.UARTEN = '1';
U1MODEBITS.UARTEN = '1';

or different values

U1MODEbits.UARTEN = 0b1;
U1MODEbits.UARTEN = 1;

but no LUCK, any ideas what am I doing wrong?

---- main.c ----

// PIC24 HEADER
#include "p24FJ192GA106.h"
// CONFIGURATION WORDS 2
#pragma config POSCMOD = NONE           // Primary Oscillator Select (Primary oscillator disabled)
#pragma config IOL1WAY = OFF            // IOLOCK One-Way Set Enable bit (Unlimited Writes To RP Registers)
#pragma config OSCIOFNC = OFF           // Primary Oscillator Output Function (OSCO functions as CLKO (FOSC/2))
#pragma config FCKSM = CSDCMD           // Clock Switching and Monitor (Both Clock Switching and Fail-safe Clock Monitor are disabled)
#pragma config FNOSC = FRCDIV           // Oscillator Select (Fast RC oscillator with Postscaler (FRCDIV))
#pragma config IESO = ON                // Internal External Switch Over Mode (IESO mode (Two-speed start-up) enabled)
// CONFIGURATION WORDS 1
#pragma config WDTPS = PS32768          // Watchdog Timer Postscaler (1:32,768)
#pragma config FWPSA = PR128            // WDT Prescaler (Prescaler ratio of 1:128)
#pragma config WINDIS = OFF             // Watchdog Timer Window (Standard Watchdog Timer is enabled,(Windowed-mode is disabled))
#pragma config FWDTEN = OFF             // Watchdog Timer Enable (Watchdog Timer is disabled)
#pragma config ICS = PGx1               // Comm Channel Select (Emulator functions are shared with PGEC1/PGED1)
#pragma config GWRP = OFF               // General Code Segment Write Protect (Writes to program memory are allowed)
#pragma config GCP = OFF                // General Code Segment Code Protect (Code protection is disabled)
#pragma config JTAGEN = ON              // JTAG Port Enable (JTAG port is enabled)

int main() {

    U1MODEbits.UARTEN = 1; // Unable to resolve identifier U1MODEbits

    U1MODEbits.UARTEN = 1; // above mentioned problem during compilation

    while(1){};

};

Solution

  • U1MODEbits.UARTEN = 1; is the correct syntax, '1' is definitely wrong because it represents the character '1', which is 0x31.

    Also Unable to resolve identifier is not a compiler error, but a message given by MPLABX (when it underline in red). MPLABX can often give false red lines, so you shouldn't rely on it too much and compile anyway.