【原创】SD卡WAV音乐播放器（quartus11.0）（FAT32）（DE2-115）
准备工具：格式工厂，Windows录音机，SD卡（小于等于2G），音箱
首先，选一首MP3，用格式工场转化成WAV格式。可以看到转化后的文件变得很大，因为WAV就是AD采样值加个文件头，所以数据量巨大，这也是MP3压缩算法流行的原因。
将转化后的WAV文件用Windows录音机打开编辑，采样率设置为8Khz,16位立体声，然后写入到SD卡里，恩，这里提一句，可以写入任意数量的歌曲，我写的程序是播放完卡里所有的WAV文件。当然别放其他文件例如图片文件进去捣乱啊，文件系统里没有识别其他文件的过程，开学了，要忙活了就没做。
硬件搭建：
SD卡的部分就不说了，前面博客提过了。说说WM8731吧，我们管这个芯片叫霸气闪耀，因为它里面有24位的ADC和DAC，而且是CD音质，听起来感觉不错的。驱动芯片首先当然是看手册，50多页的手册，还凑合。我们关心的只有几个部分：DAC，控制接口，数据接口。先来看看它的框图：
由于我们是将SD卡里的数字数据读出来，写入DAC，所以我们不管ADC的部分，注意这三个红圈，上面的红圈是控制接口，是用户控制8731工作模式写命令的接口，接口采用I2C协议；右边的红圈是耳机输出，默认是静音，坑爹啊，这个设置一样要改，不然没声的。下面的红圈是数据接口，我们的数据数据从这里串行输入。好，明确了这些概念后，我们来看8731的控制寄存器。如下图：
8731一共11个寄存器，保守起见，每个都设置一遍最好。这里还有个坑爹的地方，开始看手册不细，被耍的够惨。这个复位寄存器，当我们写入复位命令后，8731就将所有的控制寄存器先写入0.本来一上电，8731会自己复位，并且自动配置寄存器的值，但是这个软件复位的效果和上电复位的不一样，上电复位后控制寄存器里的值不是0，而是一些默认的设置，软件复位后，所有的都是零了。
扯一扯I2C协议
I2C协议点对点传输还是比较简单的，不用考虑仲裁等乱七八糟的事。8731的I2C协议如下图所示：
注意8731的设备号是可变的，而DE2-115上已经将其固定为0X34了，最后一位是读写选择，8731是只写的，不能读，所以地址加上R/W位就是0X34。发送完8位设备地址加读写位后，接下来发送16位数据，前7位是8731内部寄存器的地址，后9位是寄存器配置的数据。每一个命令封装成24位的一帧，每次发送命令都要完整的发送：起始标志，设备号，读写位，7位寄存器地址，9位数据。
命令接口说完了，接下来是数据接口，这个有些麻烦。我们要写入串行的数据，就要自己写并转串的接口。数据写入有四种模式：左对齐，I2S，和右对齐，DSP模式。继续看手册：
左对齐模式，也是我采用的模式，数据在DACLRCK的下降沿后BCLK的第一个上升沿就有效。
I2S模式，数据会延迟一个BCLK才有效。
右对齐模式，就是数据最高位和DACLRCK的下降沿对齐。
不在以DACLRCK的高低电平来区分左右声道了。数据时连续的。
我们采用左对齐方式，用硬件去实现高速的并转串接口。在检测到DACLRCK的下降沿或者上升沿后，使能模16计数器，当计数器计满时，使计数使能无效。在计数过程中，将并行数据移位输出到DACDAT引脚上。模块代码如下：
/*
*this file is use to connect the dule port ram and 8731
*when the up edge of lrck,read from the ram,and when the down edge of lrck,increace the ram address
*when the up edge of bclk,shift the 64 regs,and the msb is out to the 8731 dacda pin
*/
module data_64
(
input clk,
input rst_n,
input [31:0]q,
input bclk,
input lrck,
output q_out,
output rd_en,
output [16:0]ram_addr
);
//**************************************************************************************************
//up and down edge of lrck detect module
reg latch0;
reg latch1;
always@(posedge clk or negedge rst_n)
begin
if(!rst_n)
begin
latch0<=1'b0;
latch1<=1'b0;
end
else
begin
latch0<=lrck;
latch1<=latch0;
end
end
wire up_detect;
wire down_detect;
assign up_detect=latch0 && (~latch1);
assign rd_en=up_detect;
assign down_detect=latch1 && (~latch0);
//****************************************************************************************************************
//up and down edge of bclk detect module
reg latch2;
reg latch3;
always@(posedge clk or negedge rst_n)
begin
if(!rst_n)
begin
latch2<=1'b0;
latch3<=1'b0;
end
else
begin
latch2<=bclk;
latch3<=latch2;
end
end
wire up;
wire down;
assign up=latch2 && (~latch3);
assign down=latch3 && (~latch2);
//************************************************************************************************************
//latch up_detect module,delay the up_detect for one clk for the data read from ram
reg write;
always@(posedge clk or negedge rst_n)
begin
if(!rst_n)
write<=1'b0;
else
write<=up_detect;
end
//*************************************************************************************************************
//64 reg module
reg[31:0]data;
wire[23:0]gnd;
wire shift;
assign gnd=24'b0;
assign shift=1'b0;
always@(posedge clk or negedge rst_n)
begin
if(!rst_n)
data<=32'b0;
else if(write)
data<=q[31:0];
else if(up && en)
data<={data[30:0],shift};
end
assign q_out=data[31];
//************************************************************************************************************
//ram addr generater
reg[16:0]addr;
always@(posedge clk or negedge rst_n)
begin
if(!rst_n)
addr<=17'b0;
else if((addr==17'b11111_1111_1111_1111) && (down_detect ||up_detect))
addr<=15'b0;
else if(down_detect ||up_detect)
addr<=addr+1'b1;
end
assign ram_addr=addr;
//************************************************************************************************************
//counter enable module
reg en;
always@(posedge clk or negedge rst_n)
begin
if(!rst_n)
en<=1'b0;
else if(cnt_over)
en<=1'b0;
else if(up_detect || down_detect)
en<=1'b1;
end
//*************************************************************************************************************
//16 bits counter,count the BCLK posedge
reg[7:0]cnt;
wire cnt_over;
wire not_over;
always@(posedge clk or negedge rst_n)
begin
if(!rst_n)
begin
cnt<=8'b0;
// cnt_over<=1'b0;
end
else if((cnt==8'd16) && en )
begin
cnt<=8'b0;
// cnt_over<=1'b1;
end
else if(en && up)
begin
cnt<=cnt+1'b1;
// cnt_over<=1'b0;
end
end
assign cnt_over=(cnt==8'd16)?1'b1:1'b0;
assign not_over=~cnt_over;
endmodule
本来这个模块式用来从ram里读数据的，后来发现ram只能缓存很小的数据，就改用FIFO了，但是地址线没有去掉。
建立一个FIFO来缓冲数据，数据位宽为32位，1024*32bit大小，其实用256*32bit也可以的。利用FIFO里面的WRUSEW的最高位（就是FIFO一半满时的标记），来决定是否写入数据。如图：
写请求是软件发出的，宽度不确定，那么我们写一个模块来检测它的上升沿，在上升沿出现时，产生一个clk宽度的信号，来向fifo写入数据。clk为100M。
module wr_req_detect
(
input clk,
input rst_n,
input wr_req,
output wr_req_detect
);
reg latch0;
reg latch1;
reg latch2;
always@(posedge clk or negedge rst_n)
begin
if(!rst_n)
begin
latch0<=1'b0;
latch1<=1'b0;
latch2<=1'b0;
end
else
begin
latch0<=wr_req;
latch1<=latch0;
latch2<=latch1;
end
end
assign wr_req_detect=latch0 && (~latch1);
endmodule
如果是assign wr_req_detect=latch0 && (~latch2);那么就是产生了2个clk宽度的写请求信号，具体原理不讲了，自己体会吧。
NIOS系统的搭建就是在SD卡系统的基础上多了几个PIO，分别是I2C的两条线，还有FIFO的数据线和写请求线。注意一个问题，FIFO的读写时钟全部同步到系统时钟，即用全局时钟来控制全局，利用使能时钟解决跨时钟域问题，用一个100M的时钟去检测几M的时钟的上升下降沿自然是没有问题的。
硬件就这么多可说的。
软件部分，FAT32文件系统，读取WAV跟读取BMP没有什么区别，只是后缀名不同而已，注意文件名不要搞太长，控制在8个字节内。直接贴代码了，我C语言是自学的，写的很菜，因为当时学汇编学的太狠了，导致写出来的C程序跟汇编一个味道，冗长，但是易懂，一看就明白。
头文件：
/*
* sopc.h
*
* Created on: 2011-8-10
* Author: Fu-xiaoliang
*/
#ifndef SOPC_H_
#define SOPC_H_
#include "system.h"
#define _LED
typedef struct
{
unsigned long int DATA;
unsigned long int DIRECTION;
unsigned long int INTERRUPT_MASK;
unsigned long int EDGE_CAPTURE;
}PIO_STR;
#ifdef _LED
#define SD_DA ((PIO_STR *)SD_DA_BASE)
#define SD_CMD ((PIO_STR *)SD_CMD_BASE)
#define SD_CS ((PIO_STR *)SD_CS_N_BASE)
#define SD_CLK ((PIO_STR *)SD_CLK_BASE)
#define WR_ADDR ((PIO_STR *)WR_ADDR_BASE)
#define WR_CLK ((PIO_STR *)WR_CLK_BASE)
#define WR_DAT ((PIO_STR *)WR_DAT_BASE)
#define WR_EN ((PIO_STR *)WR_EN_BASE)
#define WR_USE_W ((PIO_STR *)WR_USE_W_BASE)
#define RD_EN ((PIO_STR *)RD_EN_BASE)
#define I2C_DAT ((PIO_STR *)I2C_DAT_BASE)
#define I2C_SCLK ((PIO_STR *)I2C_SCLK_BASE)
#define LED ((PIO_STR *)LED_BASE)
#define _SD
#endif
#ifdef _SD
#define data (SD_DA->DATA)
#define cmd (SD_CMD->DATA)
#define cs (SD_CS->DATA)
#define clk (SD_CLK->DATA)
#endif
#define uc unsigned char
#endif /* SOPC_H_ */
主函数：
/*
* "Hello World" example.
*
* This example prints 'Hello from Nios II' to the STDOUT stream. It runs on
* the Nios II 'standard', 'full_featured', 'fast', and 'low_cost' example
* designs. It runs with or without the MicroC/OS-II RTOS and requires a STDOUT
* device in your system's hardware.
* The memory footprint of this hosted application is ~69 kbytes by default
* using the standard reference design.
*
* For a reduced footprint version of this template, and an explanation of how
* to reduce the memory footprint for a given application, see the
* "small_hello_world" template.
*
*/
#include <stdio.h>
#include "alt_types.h" // alt_u32
#include <unistd.h>
#include "sys/alt_irq.h"
#include "D:\FPGA-PROJECT\myself\SD_WAV_DE2\software\DE2_SD_WAV\inc\sopc.h"
//****************************************************************************************************************************
//static variable
uc Resp_buffer[16]={0};
uc data_buffer[512]={0};
uc data_buffer1[512]={0};
unsigned long int FDT_DIRECT[16]={0};
uc not_finish=0;
unsigned long int DBR_ADDR=0;
unsigned long int FAT1_ADDR=0;
unsigned long int FAT2_ADDR=0;
unsigned long int FDT_ADDR=0;
unsigned long int CLUS_ADDR=0;
unsigned long int CLUS_CURRENT=0;//current clus number
unsigned long int CLUS_LEN=0;//clus lenth
unsigned long int CLUS_NEXT=0;
unsigned long int RAM_ADDR=0;
struct
{
union
{
unsigned char CSD[16];
unsigned char CSD1[16];
}CSD_DA;
union
{
unsigned char buf1[16];
unsigned char buf2[16];
}CID_DA;
}REG;
struct
{
uc RIFF_ID[4];
unsigned long long int WAV_SIZE;
uc RIFF_TYPE[4];
}WAV_RIFF_CHUNK;
struct
{
uc FORMAT_ID[4];
unsigned long long int FORMAT_SIZE;
unsigned long int FORMAT_TAG;
unsigned long int CHANNELS;
unsigned long long int SAMPLES_PER_SEC;
unsigned long long int BYTE_PER_SEC;
unsigned long int BLOCK_ALIGN;
unsigned long int BITS_PER_SAMPLE;
unsigned long int ADDITION;
}WAV_FORMAT_CHUNK;
struct
{
uc FACT_ID[4];
unsigned long long int FACT_SIZE;
unsigned long long int FACT_DATA;
}WAV_FACT_CHUNK;
struct
{
uc DATA_ID[4];
unsigned long long int DATA_SIZE;
}WAV_DATA_CHUNK;
//*********************************************************************************************************************************************
//function define and statement
uc send_byte(uc sda)
{
uc cnt=0,rda=0;
SD_CLK->DATA=1;
SD_CMD->DIRECTION=1;
for(cnt=0;cnt<8;cnt++)
{
SD_CLK->DATA=0;
SD_CMD->DATA=0;
if(sda & 0x80)
SD_CMD->DATA=1;
usleep(50);
sda=sda<<1;
rda=rda<<1;
SD_CLK->DATA=1;
if(SD_DA->DATA)
{
rda=rda|0x01;
}
}
SD_CLK->DATA=1;
return rda;
}
uc send_byte_fast(uc sda)
{
uc cnt=0,rda=0;
SD_CLK->DATA=1;
SD_CMD->DIRECTION=1;
for(cnt=0;cnt<8;cnt++)
{
SD_CLK->DATA=0;
SD_CMD->DATA=0;
if(sda & 0x80)
SD_CMD->DATA=1;
// usleep(70);
sda=sda<<1;
rda=rda<<1;
SD_CLK->DATA=1;
if(SD_DA->DATA)
{
rda=rda|0x01;
}
}
SD_CLK->DATA=1;
return rda;
}
uc i2c_send_3byte(uc x,uc y,uc z)
{
uc i=0;uc a=0;
I2C_SCLK->DATA=0;
I2C_DAT->DIRECTION=1;
I2C_DAT->DATA=1;
I2C_SCLK->DATA=1;//initial I2C clk and data line
usleep(10);
I2C_DAT->DATA=0;//start transfer
usleep(10);
I2C_SCLK->DATA=0;
usleep(10);
for(i=0;i<8;i++)//send first byte
{
usleep(10);
I2C_DAT->DATA=(x & 0x80)?1:0;
I2C_SCLK->DATA=1;
x=x<<1;
usleep(10);
I2C_SCLK->DATA=0;
}
I2C_DAT->DIRECTION=0;
I2C_SCLK->DATA=1;
usleep(10);
a=I2C_DAT->DATA;
if(a==0)
{
printf("slave replay first byte!\n");
}
else
printf("slave no replay !\n");
I2C_DAT->DIRECTION=1;
I2C_SCLK->DATA=0;
usleep(10);
for(i=0;i<8;i++)//send second byte
{
I2C_DAT->DATA=(y & 0x80)?1:0;
usleep(10);
I2C_SCLK->DATA=1;
y=y<<1;
usleep(10);
I2C_SCLK->DATA=0;
}
I2C_DAT->DIRECTION=0;
I2C_SCLK->DATA=1;
usleep(10);
a=I2C_DAT->DATA;
if(a==0)
{
printf("slave replay second byte!\n");
}
else
printf("slave no replay !\n");
I2C_DAT->DIRECTION=1;
I2C_SCLK->DATA=0;
usleep(10);
for(i=0;i<8;i++)//send third byte
{
I2C_DAT->DATA=(z & 0x80)?1:0;
usleep(10);
I2C_SCLK->DATA=1;
z=z<<1;
usleep(10);
I2C_SCLK->DATA=0;
}
I2C_DAT->DIRECTION=0;
I2C_SCLK->DATA=1;
usleep(10);
a=I2C_DAT->DATA;
if(a==0)
{
printf("slave replay third byte!\n");
}
else
printf("slave no replay !\n");
I2C_DAT->DIRECTION=1;
I2C_SCLK->DATA=0;
I2C_DAT->DATA=0;
I2C_SCLK->DATA=1;
usleep(10);
I2C_DAT->DATA=1;//form the stop bit
return 0;
}
uc wav_init()
{
uc i=0;
for(i=0;i<4;i++)
{
WAV_RIFF_CHUNK.RIFF_ID[i]=data_buffer1[i];
WAV_RIFF_CHUNK.RIFF_TYPE[i]=data_buffer1[i+8];
}
WAV_RIFF_CHUNK. WAV_SIZE=data_buffer1[4]|(data_buffer1[5]<<8)|(data_buffer1[6]<<16)|(data_buffer1[24]);
for(i=0;i<4;i++)
{
WAV_FORMAT_CHUNK.FORMAT_ID[i]=data_buffer1[i+12];
}
WAV_FORMAT_CHUNK.FORMAT_SIZE=data_buffer1[16]|(data_buffer1[17]<<8)|(data_buffer1[18]<<16)|(data_buffer1[19]<<24);
WAV_FORMAT_CHUNK.FORMAT_TAG=data_buffer1[20]|(data_buffer1[21]<<8);
WAV_FORMAT_CHUNK.CHANNELS=data_buffer1[22]|(data_buffer1[23]<<8);
WAV_FORMAT_CHUNK.SAMPLES_PER_SEC=data_buffer1[24]|(data_buffer1[25]<<8)|(data_buffer1[26]<<16)|(data_buffer1[27]<<24);
WAV_FORMAT_CHUNK.BYTE_PER_SEC=data_buffer1[28]|(data_buffer1[29]<<8)|(data_buffer1[30]<<16)|(data_buffer1[31]<<24);
WAV_FORMAT_CHUNK.BLOCK_ALIGN=data_buffer1[32]|(data_buffer1[33]<<8);
WAV_FORMAT_CHUNK.BITS_PER_SAMPLE=data_buffer1[34]|(data_buffer1[35]<<8);
WAV_FORMAT_CHUNK.ADDITION=data_buffer1[36]|(data_buffer1[37]<<8);
for(i=0;i<4;i++)
{
WAV_FACT_CHUNK.FACT_ID[i]=data_buffer1[i+38];
}
WAV_FACT_CHUNK.FACT_SIZE=data_buffer1[42]|(data_buffer1[43]<<8)|(data_buffer1[44]<<16)|(data_buffer1[45]<<24);
WAV_FACT_CHUNK.FACT_DATA=data_buffer1[46]|(data_buffer1[47]<<8)|(data_buffer1[48]<<16)|(data_buffer1[49]<<24);
for(i=0;i<4;i++)
{
WAV_DATA_CHUNK.DATA_ID[i]=data_buffer1[i+50];
}
WAV_DATA_CHUNK.DATA_SIZE=data_buffer1[54]|(data_buffer1[55]<<8)|(data_buffer1[56]<<16)|(data_buffer1[57]<<24);
return 0;
}
uc wm8731_init()
{
i2c_send_3byte(0x34,0x1e,0x00);//reset 8731
i2c_send_3byte(0x34,0x12,0x00);//inactive
i2c_send_3byte(0x34,0x00,0x17);//left volume
i2c_send_3byte(0x34,0x02,0x17);//right volume
i2c_send_3byte(0x34,0x04,0x7b);//left headphone
i2c_send_3byte(0x34,0x06,0x7b);//right headphone
i2c_send_3byte(0x34,0x08,0x3d);//select DAC channel
i2c_send_3byte(0x34,0x0a,0x00);//do not quiet
i2c_send_3byte(0x34,0x0c,0x00);//power on the device
i2c_send_3byte(0x34,0x0e,0x41);//master ,16bit and left mode
i2c_send_3byte(0x34,0x10,0x0c);//sampling clock control set normal mode,8KHZ
i2c_send_3byte(0x34,0x12,0x01);//active
i2c_send_3byte(0x34,0x12,0x00);//inactive
return 0;
}
uc write_CMD0(void)
{
uc a=0,i=0;
SD_CS->DATA=1;
send_byte(0xff);
SD_CS->DATA=0;
send_byte(0x40);
send_byte(0x00);
send_byte(0x00);
send_byte(0x00);
send_byte(0x00);
send_byte(0x95);
do
{
a=send_byte(0xff);
i++;
if(i==200)
{
printf("CMD0 no replay\n");
break;
}
}while(a!=0x01);
return a;
}
uc send_CMD(uc number,uc x,uc y,uc z,uc w, uc u,uc v,uc r)
{
uc b=0,i=0;
SD_CS->DATA=1;
send_byte_fast(0xff);
SD_CS->DATA=0;
send_byte_fast(x);
send_byte_fast(y);
send_byte_fast(z);
send_byte_fast(w);
send_byte_fast(u);
send_byte_fast(v);
do
{
b=send_byte_fast(0xff);
i++;
if(i==200)
{
printf("CMD%d no replay\n",number);
break;
}
}while(b!=r);
return b;
}
uc write_CMD1(void)
{
uc a=0,i=0;
SD_CS->DATA=1;
send_byte(0xff);
SD_CS->DATA=0;
send_byte(0x41);
send_byte(0x00);
send_byte(0x00);
send_byte(0x00);
send_byte(0x00);
send_byte(0xff);
do
{
a=send_byte(0xff);
i++;
if(i==200)
{
printf("CMD1 no replay\n");
break;
}
}while(a!=0x00);
return a;
}
uc sd_init(void)
{
uc i=0;
uc a,b;
SD_CS->DATA=1;
for(i=0;i<100;i++)
{
send_byte(0xff);
}
usleep(250);
i=0;
do
{
b=write_CMD0();
i++;
if(i==100)
break;
}while(b!=0x01);
printf("CMD0 replay %x\n",b);
i=0;
do
{
a=write_CMD1();
i++;
if(i==100)
break;
}while(a!=0x00);
printf("CMD1 replay %x\n",a);
i=0;
do
{
a=send_CMD(16,0x50,0x00,0x00,0x02,0x00,0xff,0x00);
i++;
if(i==10)
break;
}while(a!=0x00);
printf("CMD16 replay %x\n",a);
i=0;
do
{
a=send_CMD(59,0x7b,0x00,0x00,0x00,0x00,0xff,0x00);
i++;
if(i==10)
break;
}while(a!=0x00);
printf("CMD59 replay %x\n",a);
i=0;
do
{
a=send_CMD(9,0x49,0x00,0x00,0x00,0x00,0xff,0x00);
i++;
if(i==10)
break;
}while(a!=0x00);
printf("CMD9 replay %x\n",a);
if(a==0x00)
{
uc tem=0;
do
{
printf("tem is %x\n",tem);
tem=send_byte(0xff);
}while(tem!=0xfe);
printf("tem is %x\n",tem);
if(tem==0xfe)
{
printf("0xfe is received\n");
for(i=0;i<16;i++)
{
Resp_buffer[i]=send_byte(0xff);
}
send_byte(0xff);
send_byte(0xff);
SD_CS->DATA=1;
send_byte(0xff);
}
}
for(i=0;i<16;i++)
{
printf("CSD is %x\n",Resp_buffer[i]);
REG.CSD_DA.CSD[i]=Resp_buffer[i];
}
return 0;
}
void ISR_neg(void *context,unsigned long id)
{
/* i=0;
do{
a=send_CMD(17,0x51,(((CLUS_ADDR+512*k)&0xff000000)>>24),(((CLUS_ADDR+512*k)&0x00ff0000)>>16),(((CLUS_ADDR+512*k)&0x0000ff00)>>8),((CLUS_ADDR+512*k)&0xff),0xff,0x00);
i++;
if(i==100)
break;
}while(a!=0x00);
if(a==0x00)
{
uc temp=0;
int j=0;;
do{
temp=send_byte_fast(0xff);
j++;
}while(temp!=0xfe && j<100);*/
int j;
for(j=0;j<509;j=j+4)
{
data_buffer1[j]=send_byte_fast(0xff);
data_buffer1[j+1]=send_byte_fast(0xff);
data_buffer1[j+2]=send_byte_fast(0xff);
data_buffer1[j+3]=send_byte_fast(0xff);
if((data_buffer1[0]==0x52) && (data_buffer1[1]=0x49) && (data_buffer1[2]==0x46) && (data_buffer1[3]==0x46))
{
if(j>=58)
{
WR_EN->DATA=0;
WR_DAT->DATA=data_buffer1[j]|(data_buffer1[j+1]<<8)|(data_buffer1[j+2]<<16)|(data_buffer1[j+3]<<24);
WR_EN->DATA=1;
}
}
else
{
WR_EN->DATA=0;
WR_DAT->DATA=data_buffer1[j]|(data_buffer1[j+1]<<8)|(data_buffer1[j+2]<<16)|(data_buffer1[j+3]<<24);
WR_EN->DATA=1;
}
}
}
int init_neg(void)
{
WR_USE_W->INTERRUPT_MASK=1;
return alt_irq_register(WR_USE_W_IRQ,NULL,ISR_neg);
}
//*********************************************************************************************************************************************
//the main function
int main()
{
int i=0,j=0,k=0,cnt=0;
unsigned int index=0;
uc a;
for(i=0;i<8;i++)
{
LED->DATA=1<<i;
usleep(500000);
}
SD_CS->DATA=1;
SD_CMD->DIRECTION=1;
SD_CMD->DATA=1;
sd_init();
wm8731_init();
i=0;
do
{
a=send_CMD(10,0x4a,0x00,0x00,0x00,0x00,0xff,0x00);
i++;
if(i==10)
break;
}while(a!=0x00);
printf("CMD10 replay %x\n",a);
if(a==0x00)
{
uc tem=0;
do
{
printf("tem is %x\n",tem);
tem=send_byte(0xff);
}while(tem!=0xfe);
printf("tem is %x\n",tem);
if(tem==0xfe)
{
printf("0xfe is received\n");
for(i=0;i<16;i++)
{
Resp_buffer[i]=send_byte(0xff);
}
send_byte(0xff);
send_byte(0xff);
SD_CS->DATA=1;
send_byte(0xff);
}
for(i=0;i<16;i++)
{
printf("CID is %x\n",Resp_buffer[i]);
REG.CID_DA.buf1[i]=Resp_buffer[i];
}
}
i=0;
do
{
a=send_CMD(17,0x51,0x00,0x00,0x00,0x00,0xff,0x00);
i++;
if(i==100)
break;
}while(a!=0x00);
printf("CMD17 replay %x\n",a);
if(a==0x00)
{
uc temp=0;
int j=0;;
do{
printf("temp is %x\n",temp);
temp=send_byte_fast(0xff);
j++;
}while(temp!=0xfe && j<100);
printf("temp is %x\n",temp);
if(temp==0xfe)
{
printf("0xfe is received\n");
printf("block 0 data is followed\n");
for(j=0;j<512;j++)
{
data_buffer[j]=send_byte_fast(0xff);
}
i=0;
for(j=0;j<512;j++)
{
printf("%x ",data_buffer[j]);
i++;
if(i==16)
{
i=0;
printf("\n");
}
}
}
}
if((data_buffer[0]==0x00)||(data_buffer[0]!=0xeb)||(data_buffer[0]!=0xe9))//judge the weather first block is DBR or not
{
DBR_ADDR=(((DBR_ADDR|data_buffer[457])<<24)|((DBR_ADDR|data_buffer[456])<<16)|((DBR_ADDR|data_buffer[455])<<8)|data_buffer[454])*512;
i=0;
do{
a=send_CMD(17,0x51,((DBR_ADDR&0xff000000)>>24),((DBR_ADDR&0x00ff0000)>>16),((DBR_ADDR&0x0000ff00)>>8),(DBR_ADDR&0xff),0xff,0x00);
i++;
if(i==100)
break;
}while(a!=0x00);
if(a==0x00)
{
uc temp=0;
int j=0;;
do{
printf("temp is %x\n",temp);
temp=send_byte_fast(0xff);
j++;
}while(temp!=0xfe && j<100);
printf("temp is %x\n",temp);
if(temp==0xfe)
{
printf("0xfe is received\n");
printf("DBR data is followed\n");
for(j=0;j<512;j++)
{
data_buffer[j]=send_byte_fast(0xff);
}
i=0;
for(j=0;j<512;j++)
{
printf("%x ",data_buffer[j]);
i++;
if(i==16)
{
i=0;
printf("\n");
}
}
}
}
}
else
{
DBR_ADDR=0;
}
FAT1_ADDR=DBR_ADDR+((data_buffer[14]|(data_buffer[15]<<8))*512);
FAT2_ADDR=FAT1_ADDR+((data_buffer[36]|(data_buffer[37]<<8))*512);
FDT_ADDR=FAT2_ADDR+((data_buffer[36]|(data_buffer[37]<<8))*512);
CLUS_LEN=data_buffer[13]*512;
printf("FAT1_ADDR is %lx \n",FAT1_ADDR);
printf("FAT2_ADDR is %lx \n",FAT2_ADDR);
printf("FDT_ADDR is %lx \n",FDT_ADDR);
printf("DBR_ADDR is %lx \n",DBR_ADDR);
printf("CLUS_LEN is %lx \n",CLUS_LEN);
i=0;
do{
//read the FDT
a=send_CMD(17,0x51,((FDT_ADDR&0xff000000)>>24),((FDT_ADDR&0x00ff0000)>>16),((FDT_ADDR&0x0000ff00)>>8),(FDT_ADDR&0xff),0xff,0x00);
i++;
if(i==100)
break;
}while(a!=0x00);
if(a==0x00)
{
uc temp=0;
int j=0;
do{
printf("temp is %x\n",temp);
temp=send_byte_fast(0xff);
j++;
}while(temp!=0xfe && j<100);
printf("temp is %x\n",temp);
if(temp==0xfe)
{
printf("0xfe is received\n");
printf("FDT data is followed\n");
for(j=0;j<512;j++)
{
data_buffer[j]=send_byte_fast(0xff);
}
i=0;
for(j=0;j<512;j++)
{
printf("%x ",data_buffer[j]);
i++;
if(i==16)
{
i=0;
printf("\n");
}
}
}
}
for(i=0,j=0;i<512;i=i+32)
{
if((data_buffer[11+i]==0x08)&&(data_buffer[i]!=0xe5))//find the juan biao
{
printf("juan biao is %d\n",i+11);
continue;
}
else if((data_buffer[11+i]==0x20)&&(data_buffer[i]!=0xe5))//find the file
{
CLUS_CURRENT=(data_buffer[20+i]<<16)|(data_buffer[21+i]<<24)|(data_buffer[27+i]<<8)|(data_buffer[26+i]);//first clus addr
printf("first clus is %ld\n",CLUS_CURRENT);
FDT_DIRECT[j]=CLUS_CURRENT;//store the current clus addr
j++;
continue;
}
else if(data_buffer[i]==0xe5)
continue;
else if(data_buffer[i]==0x00)
{
break;
not_finish=0;//no file behind
}
}
i=0;
do{
//read FAT1
a=send_CMD(17,0x51,((FAT1_ADDR&0xff000000)>>24),((FAT1_ADDR&0x00ff0000)>>16),((FAT1_ADDR&0x0000ff00)>>8),(FAT1_ADDR&0xff),0xff,0x00);
i++;
if(i==100)
break;
}while(a!=0x00);
if(a==0x00)
{
uc temp=0;
int j=0;;
do{
printf("temp is %x\n",temp);
temp=send_byte_fast(0xff);
j++;
}while(temp!=0xfe && j<100);
printf("temp is %x\n",temp);
if(temp==0xfe)
{
printf("0xfe is received\n");
printf("FAT1 data is followed\n");
for(j=0;j<512;j++)
{
data_buffer[j]=send_byte_fast(0xff);
}
i=0;
for(j=0;j<512;j++)
{
printf("%x ",data_buffer[j]);
i++;
if(i==16)
{
i=0;
printf("\n");
}
}
}
}
CLUS_ADDR=(FDT_DIRECT[0]-2)*CLUS_LEN+FDT_ADDR;//first data clus address
CLUS_NEXT=data_buffer[(FDT_DIRECT[0]*4)]|(data_buffer[(FDT_DIRECT[0]*4+1)]<<8)|(data_buffer[(FDT_DIRECT[0]*4+2)]<<16)|(data_buffer[(FDT_DIRECT[0]*4+3)]<<24);
// CLUS_ADDR=(CLUS_CURRENT-2)*CLUS_LEN+FDT_ADDR;//first data clus address
// CLUS_NEXT=data_buffer[CLUS_CURRENT*4]|(data_buffer[CLUS_CURRENT*4+1]<<8)|(data_buffer[CLUS_CURRENT*4+2]<<16)|(data_buffer[CLUS_CURRENT*4+3]<<24);
// printf("CLUS_NEXT is %lx\n",CLUS_NEXT);
index=0;
cnt=0;
do{
do{
CLUS_ADDR=(FDT_DIRECT[cnt]-2)*CLUS_LEN+FDT_ADDR;//first data clus address
FDT_DIRECT[cnt]=CLUS_NEXT;
CLUS_NEXT=FDT_DIRECT[cnt]+1;//data_buffer[(FDT_DIRECT[cnt]*4-512*index)]|(data_buffer[(FDT_DIRECT[cnt]*4+1-512*index)]<<8)|(data_buffer[(FDT_DIRECT[cnt]*4+2-512*index)]<<16)|(data_buffer[(FDT_DIRECT[cnt]*4+3-512*index)]<<24);
// FDT_DIRECT[cnt]=CLUS_NEXT;
/* if((FDT_DIRECT[cnt]*4+3)>=511)
{
FDT_DIRECT[cnt]=0;
index++;
i=0;
do{
//read FAT1 next 512 byte
a=send_CMD(17,0x51,(((FAT1_ADDR+512*index)&0xff000000)>>24),(((FAT1_ADDR+512*index)&0x00ff0000)>>16),(((FAT1_ADDR+512*index)&0x0000ff00)>>8),((FAT1_ADDR+512*index)&0xff),0xff,0x00);
i++;
if(i==100)
break;
}while(a!=0x00);
printf("a is %x\n",a);
if(a==0x00)
{
uc temp=0;
int j=0;;
do{
printf("temp is %x\n",temp);
temp=send_byte_fast(0xff);
j++;
}while(temp!=0xfe && j<100);
printf("temp is %x\n",temp);
if(temp==0xfe)
{
printf("0xfe is received\n");
printf("FAT1 next 512b data is followed\n");
for(j=0;j<512;j++)
{
data_buffer[j]=send_byte_fast(0xff);
}
i=0;
for(j=0;j<512;j++)
{
printf("%x ",data_buffer[j]);
i++;
if(i==16)
{
i=0;
printf("\n");
}
}
}
}
}*/
// CLUS_ADDR=(CLUS_CURRENT-2)*CLUS_LEN+FDT_ADDR;
// CLUS_CURRENT=CLUS_NEXT;
// CLUS_NEXT=data_buffer[CLUS_CURRENT*4]|(data_buffer[CLUS_CURRENT*4+1]<<8)|(data_buffer[CLUS_CURRENT*4+2]<<16)|(data_buffer[CLUS_CURRENT*4+3]<<24);
// for(k=0;k<8;k++)//for each clus has 8 512Byte
// {
k=0;
while(!WR_USE_W->DATA)
{
i=0;
do{
a=send_CMD(17,0x51,(((CLUS_ADDR+512*k)&0xff000000)>>24),(((CLUS_ADDR+512*k)&0x00ff0000)>>16),(((CLUS_ADDR+512*k)&0x0000ff00)>>8),((CLUS_ADDR+512*k)&0xff),0xff,0x00);
i++;
if(i==100)
break;
}while(a!=0x00);
// printf("read data a is %x\n",a);
if(a==0x00)
{
uc temp=0;
int j=0;
do{
// printf("temp is %x\n",temp);
temp=send_byte_fast(0xff);
j++;
}while(temp!=0xfe && j<100);
// printf("temp is %x\n",temp);
if(temp==0xfe)
{
// printf("0xfe is received\n");
// printf("first clus data is followed\n");
for(j=0;j<509;j=j+4)
{
data_buffer1[j]=send_byte_fast(0xff);
data_buffer1[j+1]=send_byte_fast(0xff);
data_buffer1[j+2]=send_byte_fast(0xff);
data_buffer1[j+3]=send_byte_fast(0xff);
if((data_buffer1[0]==0x52) && (data_buffer1[1]=0x49) && (data_buffer1[2]==0x46) && (data_buffer1[3]==0x46))
{
if(j>=58)
{
WR_EN->DATA=0;
WR_DAT->DATA=data_buffer1[j]|(data_buffer1[j+1]<<8)|(data_buffer1[j+2]<<16)|(data_buffer1[j+3]<<24);
WR_EN->DATA=1;
}
}
else
{
WR_EN->DATA=0;
WR_DAT->DATA=data_buffer1[j]|(data_buffer1[j+1]<<8)|(data_buffer1[j+2]<<16)|(data_buffer1[j+3]<<24);
WR_EN->DATA=1;
}
}
/* i=0;
for(j=0;j<512;j++)
{
usleep(10);
printf("%x ",data_buffer1[j]);
i++;
if(i==16)
{
i=0;
printf("\n");
}
}*/
}
}
k++;
// if(k==8)
// break;
}
i2c_send_3byte(0x34,0x12,0x01);//active
// printf("enable display!\n");
// while(WR_USE_W->DATA);
while(1)
{
while(!WR_USE_W->DATA)
{
i=0;
do{
a=send_CMD(17,0x51,(((CLUS_ADDR+512*k)&0xff000000)>>24),(((CLUS_ADDR+512*k)&0x00ff0000)>>16),(((CLUS_ADDR+512*k)&0x0000ff00)>>8),((CLUS_ADDR+512*k)&0xff),0xff,0x00);
i++;
if(i==100)
break;
}while(a!=0x00);
if(a==0x00)
{
uc temp=0;
int j=0;
do{
// printf("temp is %x\n",temp);
temp=send_byte_fast(0xff);
j++;
}while(temp!=0xfe && j<100);
// printf("temp is %x\n",temp);
if(temp==0xfe)
{
// printf("0xfe is received\n");
// printf("first clus data is followed\n");
for(j=0;j<509;j=j+4)
{
data_buffer1[j]=send_byte_fast(0xff);
data_buffer1[j+1]=send_byte_fast(0xff);
data_buffer1[j+2]=send_byte_fast(0xff);
data_buffer1[j+3]=send_byte_fast(0xff);
/* if((data_buffer1[0]==0x52) && (data_buffer1[1]=0x49) && (data_buffer1[2]==0x46) && (data_buffer1[3]==0x46))
{
if(j>=58)
{
WR_EN->DATA=0;
WR_DAT->DATA=data_buffer1[j]|(data_buffer1[j+1]<<8)|(data_buffer1[j+2]<<16)|(data_buffer1[j+3]<<24);
WR_EN->DATA=1;
}
}*/
// else
// {
WR_EN->DATA=0;
WR_DAT->DATA=data_buffer1[j]|(data_buffer1[j+1]<<8)|(data_buffer1[j+2]<<16)|(data_buffer1[j+3]<<24);
WR_EN->DATA=1;
// }
}
}
}
k++;
if(k==8)
break;
}
if(k==8)
break;
}
// } //the for loop
}while(CLUS_NEXT!=0x0fffffff);
cnt++;
CLUS_NEXT=data_buffer[(FDT_DIRECT[cnt]*4)]|(data_buffer[(FDT_DIRECT[cnt]*4+1)]<<8)|(data_buffer[(FDT_DIRECT[cnt]*4+2)]<<16)|(data_buffer[(FDT_DIRECT[cnt]*4+3)]<<24);
}while(FDT_DIRECT[cnt]!=0);
SD_CS->DATA=1;
unsigned long int cap;
double c;
//(c_size+1)*mult*(1<<read_bl_len)
cap=((((REG.CSD_DA.CSD[6]&0x03)<<10) | (REG.CSD_DA.CSD[7]<<2) | ((REG.CSD_DA.CSD[8]&0xC0)>>6) + 1))*(1 << ((((REG.CSD_DA.CSD[9]&0x03)<<1) | ((REG.CSD_DA.CSD[10]&0x80)>>7)) + 2))*(1<<(REG.CSD_DA.CSD[5]&0x0f));
printf("capacity is %ld MB\n",cap/1048576);
printf("read_bl_len is %d B\n",(1<<(REG.CSD_DA.CSD[5]&0x0f)));
c=((double)cap/1073741824);
printf("capacity is %f GB\n",c);
printf("send CMD0!\n");
return 0;
}
有很多没用到的引脚，我没删除，留着扩展用吧，另外我没用中断，虽然生命了函数，但是是用电平检测来做的，担心中断容易出BUG。
采样频率没法再提高了，SD卡读取还是比较慢的，我尝试了32K和48K ，都失败了，放出来的声音简直是闹鬼，不过我同学说，8K的效果也很不错了，一点噪音没有。
播放结束后，手动按复位键重新开始播放，不然会将卡里的数据都用DAC播放出来，呵呵，我没检测文件簇结束标志0X0FFFFFFF，所以它会一直不停的播放下去，我也懒得改了。
我觉得应该有办法将采样频率提高到48K的，因为友晶的范例是用的44.1K的采样频率，我这篇是原创，完全没有按他们的思路来。从电路到程序全是自己搞的。
