PIC16F1503在memcpy上停止

好的，你有一个声明LCDYBuff:但是这个变量的定义在哪里？基本上，声明（任何时候使用Extn都是声明）不分配内存，只有定义才这样做。你需要的地方：



      以下为原文

    OK you have a declaration for lcd_buffer:
extern volatile char lcd_buffer[21];
but where is the definition of this variable?
Basically, declarations (anytime you use extern it is a declaration) DO NOT allocate memory only the definition does that. Somewhere you need:
volatile char lcd_buffer[21];
 

LCDY缓冲区定义在哪里？我不希望你的代码链接到它的当前状态。



      以下为原文

    Where is lcd_buffer defined?  I wouldn't expect your code to link in its current state.

init函数在它自己的C文件中。LCDAL缓冲区在main中定义，以及ISR使用的其他全局变量。这里是主文件。



      以下为原文

    The init function is in it's own c file.
 
lcd_buffer is defined in main, along with some other global variables used by the ISR.
 
Here is the main file.
 
 // Include PIC16F1503 CONFIG register settings
// These control clock selection, watchdog disable, etc
#include "pic16f1503config.h"

// Compiler include file
#include

// C Standard Includes
#include
#include

// Project Specific Includes
#include "Init.h"
#include "lcd_funcs.h"
#include "AlarmClock.h"


// Global Variables
volatile l_state lcd_state;
volatile uint8_t msg_length;
volatile unsigned char *lcd_msg;
uint8_t i2c_addr;
volatile char lcd_buffer[21];

void main(void) {
    // Initialization of MCU & peripherals
    Init();
    
    while(1){
        // The main loop of the program runs forever
        lcd_buffer[0]=0x40;
        const char testmsg[] = "This is a test";
        memcpy(lcd_buffer+1,testmsg,14);
        send2lcd(lcd_buffer,15,lcd_w);
        while(1){
            // Basically stop for test
        }
    }
    return;
}

void interrupt pic16_int (void) {
    if(SSP1IF == 1){
        // If MSSP module generated the interrupt, clear the flag and process
        LATA = 0x10;
        SSP1IF = 0;
        switch(lcd_state) {
            case lcd_idle:
                // Do Nothing
                break;
            case lcd_start:
                // Start Condition Completed, send address
                SSP1BUF = i2c_addr;
                // Then go to next state
                if(i2c_addr & 0x01){
                    // LSB '1' = TX
                    lcd_state = lcd_rx;
                } else {
                    // LSB '0' = RX
                    lcd_state = lcd_tx;
                }
                break;
            case lcd_tx:
                // Loading buffer starts transmission
                SSP1BUF = *lcd_msg;
                lcd_msg++;
                msg_length--;
                if(msg_length == 0){
                    lcd_state = lcd_stop;
                }
                break;
            case lcd_rx:
                // Grab received byte
                break;
            case lcd_stop:
                // Set Stop Bit
                SSP1CON2bits.PEN = 1;
                lcd_state = lcd_finish;
                break;
            case lcd_finish:
                // I2C Transaction is completed, go to idle
                lcd_state = lcd_idle;
        }
    }
    return;
}

只要你不需要这个：



      以下为原文

    just FYI you do not need this:
#include

我不希望“const”会影响在那个上下文中生成的代码，但是在没有“const”的情况下尝试它。



      以下为原文

    I wouldn't expect "const" to affect the generated code in that context, but try it without "const".

const是告诉编译器把它放到程序存储器和RAM中的东西。由于PIC16F503只有128个字节的RAM，所以我希望避免在可能的时候使用它。不管怎样，我试着移除它，但仍然会粘在MimcPy线上。



      以下为原文

    const is what tells the compiler to put it into program memory vs RAM. Since the PIC16F1503 only has 128 bytes of RAM I'd like to avoid using it when possible.
 
Regardless, I tried removing it but still gets stuck on that memcpy line.

我很惊讶XC8允许你在那里定义变量。它是一个“C89”编译器，其中变量定义只能出现在块的开始之前，在任何可执行代码之前。



      以下为原文

    I'm surprised XC8 allowed you to define the variable there.
It is a "C89" compiler, where variable definitions can only occur at the start of a block, before any executable code.
Have you looked at the LST file output to see what assembler has been generated there?
 
 

我没有立即看到任何东西，但我并不熟悉PIC指令集（我来自HC08的）。



      以下为原文

    I don't see anything immediately, but I'm not all that familiar with the PIC instruction set (I came from HC08's).
 
   831 ;Init.c: 76: const uint8_t lcd_init1[] = {0x00,0x38,0x39,0x14,0x78,0x5E,0x6D};
   832 ;Init.c: 77: __builtin_memcpy(lcd_buffer,lcd_init1,7);
   833 006B 3020 movlw low (_lcd_buffer| 0)
   834 006C 0086 movwf 6
   835 006D 0187 clrf 7
   836 006E 3015 movlw low (Init@lcd_init1| (0+32768))
   837 006F 0084 movwf 4
   838 0070 3081 movlw high (Init@lcd_init1| (0+32768))
   839 0071 0085 movwf 5
   840 0072 3007 movlw 7
   841 0073 00F6 movwf ??_Init
   842 0074 0876 movf ??_Init,w
   843 0075 1903 skipnz
   844 0076 287B goto l635
   845 0077 u10m0:
   846 0077 0012 moviw fsr0++
   847 0078 001E movwi fsr1++
   848 0079 0BF6 decfsz ??_Init,f
   849 007A 2877 goto u10m0
   850 007B l635:
   851
   852 ;Init.c: 78: send2lcd(lcd_buffer,7,0x78);
 
And the constant is here:
   507 psect stringtext2
   508 0115 __pstringtext2:
   509 0115 Init@lcd_init1:
   510 0115 3400 retlw 0
   511 0116 3438 retlw 56
   512 0117 3439 retlw 57
   513 0118 3414 retlw 20
   514 0119 3478 retlw 120
   515 011A 345E retlw 94
   516 011B 346D retlw 109
   517 011C __end_ofInit@lcd_init1: