寄存器中的PIC24设置位

Question

我正在用C语言用PIC24FJ192GA106编译器在MPLABX中为XC16编写一些程序，我在编译过程中遇到了以下问题

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

问题是：

U1MODE.UARTEN = '1';

U1MODE是在#include "p24FJ192GA106.h“中定义的结构(头包含在文件中)，其结构如下

`#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__));`

我也试过

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

或不同的价值

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

但是没有运气，有什么想法我做错了什么？

// 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){};

};

Answer 1

U1MODEbits.UARTEN = 1;是正确的语法，'1'无疑是错误的，因为它表示字符'1'，即0x31。

另外，Unable to resolve identifier不是编译器错误，而是由MPLABX提供的消息(当它以红色下划线时)。MPLABX经常会给出错误的红线，所以您不应该过多地依赖它并编译。