XC16将数据表放入PSV内存(PIC)

Question

我想在Flash中放一个表，然后直接从我的C程序中读取它。根据microchip的说法，这是由__attribute__((space(psv)))完成的，然而，由于Microchip周围的大多数事情，他们自己的例子工作得不是很好(通常是过时的，没有更新)：https://microchipdeveloper.com/16bit:psv

所以这就是我想要做的：

uint16_t __attribute__((space(psv))) ConfDiskImage[] = {
    /*AOUT*/ 0x01E0,0x0004,0x3333,0x4053,
    /*   1*/ 0x01E1,0x0012,0x0005,0x0000,0x0000,0x0000,0x4120,0x0000,0x0000,0x0000,0x4120,
    /*   2*/ 0x01E2,0x0012,0x0006,0x0000,0x0000,0x0000,0x4120,0x0000,0x0000,0x0000,0x4120,
    /*   3*/ 0x01E3,0x0012,0x0007,0x0000,0x0000,0x0000,0x4120,0x0000,0x0000,0x0000,0x4120,
    /*EOD */ 0x0000,0x0000
};

当我编译时，我得到："warning: ignoring space attribute applied to automatic ConfDiskImage"

我使用的是MPLAB 5.45和XC16--gcc v1.50。单片机: dsPIC33EP256MC506

有没有办法让它留在闪存中(而不是复制到RAM中)，并用指针直接从闪存中读取？

Answer 1

我怀疑您真正需要的可能是更复杂的东西，但是对于您提出的问题，简单的答案是使用const存储类。

例如：

/*
 * File:   main.c
 * Author: dan1138
 * Target: dsPIC33EP256MC506
 * Compiler: XC16 v1.61
 * IDE: MPLABX v5.45
 *
 * Created on February 19, 2021, 11:56 PM
 */

#pragma config ICS = PGD2, JTAGEN = OFF, ALTI2C1 = OFF, ALTI2C2 = OFF, WDTWIN = WIN25
#pragma config WDTPOST = PS32768, WDTPRE = PR128, PLLKEN = ON, WINDIS = OFF
#pragma config FWDTEN = OFF, POSCMD = NONE, OSCIOFNC = ON, IOL1WAY = OFF, FCKSM = CSECMD
#pragma config FNOSC = FRCDIVN, PWMLOCK = OFF, IESO = ON, GWRP = OFF, GCP = OFF

#include "xc.h"

const uint16_t ConfDiskImage[] = {
    /*AOUT*/ 0x01E0,0x0004,0x3333,0x4053,
    /*   1*/ 0x01E1,0x0012,0x0005,0x0000,0x0000,0x0000,0x4120,0x0000,0x0000,0x0000,0x4120,
    /*   2*/ 0x01E2,0x0012,0x0006,0x0000,0x0000,0x0000,0x4120,0x0000,0x0000,0x0000,0x4120,
    /*   3*/ 0x01E3,0x0012,0x0007,0x0000,0x0000,0x0000,0x4120,0x0000,0x0000,0x0000,0x4120,
    /*EOD */ 0x0000,0x0000
};

int main(void) 
{
    const uint16_t *pData;
    
    pData = ConfDiskImage; /* point to the start of the image */
    /*
     * Walk the image
     */
    for(;;)
    {
        if((!*pData) && (!*pData+1))
        {
            /* At end of image point to the start */
            pData = ConfDiskImage;
        }
        pData++; /* skip record type */
        pData += 1+*pData/2;
    }
    return 0;
}