基于FPGA(cyclone IV)的NOR FLASH的应用
基于FPGA(cyclone IV)的NOR FLASH的应用
1.器件挂载到QSYS的三态驱动器上；
2. 查阅datasheet,配置时序；
3.编译，参考“黑金”或者“微雪”的例程…
实际工程使用S29GL512P,EPCS选用EPCS64,IS61WV51216该系统搭载十分豪华配置…
NOR FLASH 容量 512Mbits,64MB,
EPCS 64Mbit,8MB,
不用sdram,避免时钟相位问题
在NIOS II Eclipse中，第一行中include “sys/alt_flash.h”，包含着FLASH库函数
,nor flash 中的地址宽度为0x3fff_ffff（该参数位QSYS中对齐数据位用）,实际的25根地址线，寻址范围位2^25 =512*63335,所以共512个Block,1个region,每个Block为0x10000,所以FLASH_OFFSET 值不宜乱取。由于flash本身的性质，如果要擦除位于某一个block中的某个地址（哪怕仅仅是一个），整个block的内容都会被擦除（全1）。
下面是的基本flash操作函数：
alt_flash_open_dev(),
alt_write_flash(),
alt_read_flash(),
alt_flash_close_dev()，
alt_get_flash_info()，
alt_erase_flash_block()，
alt_write_flash_block()，
1 #include "sys/alt_flash.h"
2 #include
3 #include
4 #include
5
6 #define BUF_SIZE 1024
7 #define FLASH_OFFSET 0x50000//偏移地址，实际为第六个Block
8
9 int main()
10 {
11 printf("Fuck Nios II!\n");
12
13 int i;
14 alt_flash_fd* fd;
15 flash_region* regions;
16 int number_of_regions;
17 int ret_code = 0x0;
18 unsigned char source[BUF_SIZE];
19 unsigned char dest[BUF_SIZE];
20
21 unsigned char block_dest[0x2000];
22
23 for(i=0;i<100;i++){
24 source[i] = i;
25 }
26 fd = alt_flash_open_dev("/dev/cfi_flash");
27 printf("flash opening...\n"); //Debug
28 //fd = alt_flash_open_dev(“/dev/epcs_flash”); //EPCSX
29 if (fd){
30 printf("flash opened\n"); //Debug
31 printf("fd is %d\n",fd); //Debug
32 ret_code = alt_get_flash_info(fd, ®ions, &number_of_regions);
33 for(i=0;ioffset,
36 (regions+i)->region_size+(regions+i)->offset,
37 (regions+i)->number_of_blocks,
38 (regions+i)->block_size);
39 }
40 alt_erase_flash_block(fd, FLASH_OFFSET, BUF_SIZE);
41
42 /* //////////////////////////////////////////////////////////
43 ///// the entire block is erased to 1 //////
44 //////////////////////////////////////////////////////////
45 ret_code = alt_read_flash(fd,0x4000,block_dest,0x2000);///
46 if(ret_code != 0){ //
47 printf("Can't read flash device\n"); //
48 exit(-1); //
49 } //
50 else{ //
51 printf("Read Flash Device Successfully.\n"); //
52 } //
53 // Print the destination data //
54 for(i=0;i<0x2000;i++){ //
55 printf("OFFSET_Address %4d is %d\n",i,block_dest[i]);
56 } //
57 //////////////////////////////////////////////////////////*/
58
59 ret_code = alt_read_flash(fd,FLASH_OFFSET,dest,BUF_SIZE);
60 if(ret_code != 0){
61 printf("Can't read flash device\n");
62 exit(-1);
63 }
64 else{
65 printf("Read Flash Device Successfully.\n");
66 }
67 // Print the destination data
68 for(i=0;i<100;i++){
69 printf("OFFSET_Address %2d is %d\n",i,dest[i]);
70 }
71
72 ret_code = alt_write_flash(fd,FLASH_OFFSET,source,BUF_SIZE);
73 if(ret_code != 0){
74 printf("Can't write flash device\n");
75 exit(-1);
76 }
77 else{
78 printf("Write Flash Device Successfully.\n");
79 }
80
81 ret_code = alt_read_flash(fd,FLASH_OFFSET,dest,BUF_SIZE);
82 if(ret_code != 0){
83 printf("Can't read flash device\n");
84 exit(-1);
85 }
86 else{
87 printf("Read Flash Device Successfully.\n");
88 }
89
90 for(i=0;i<100;i++){
91 printf("OFFSET_Address %2d is %d\n",i,dest[i]);
92 }
93 }
94 alt_flash_close_dev(fd);
95 printf("flash closed \n");
96 }