SAM4L-EK FLASH读写、擦除操作

_烟酒僧_

SAM4L-EK板载FLASH AT25DF64的主要特性特性如下：
Features
• Single 2.7V - 3.6V Supply
• Serial Peripheral Interface (SPI) Compatible
– Supports SPI Modes 0 and 3
– Supports RapidS® Operation
– Supports Dual-Input Program and Dual-Output Read
• Very High Operating Frequencies
– 100 MHz for RapidS
– 85 MHz for SPI
– Clock-to-Output (tV) of 5 ns Maximum
• Flexible, Optimized Erase Architecture for Code + Data Storage Applications
– Uniform 4-Kbyte Block Erase
– Uniform 32-Kbyte Block Erase
– Uniform 64-Kbyte Block Erase
– Full Chip Erase
• Individual Sector Protection with Global Protect/Unprotect Feature
– 128 Sectors of 64-Kbytes Each
• Hardware Controlled Locking of Protected Sectors via WP Pin
• Sector Lockdown
– Make Any Combination of 64-Kbyte Sectors Permanently Read-Only
• 128-Byte Programmable OTP Security Register
• Flexible Programming
– Byte/Page Program (1 to 256 Bytes)
• Fast Program and Erase Times
– 1.0 ms Typical Page Program (256 Bytes) Time
– 50 ms Typical 4-Kbyte Block Erase Time
– 250 ms Typical 32-Kbyte Block Erase Time
– 400 ms Typical 64-Kbyte Block Erase Time
• Program and Erase Suspend/Resume
• Automatic Checking and Reporting of Erase/Program Failures
• Software Controlled Reset
• JEDEC Standard Manufacturer and Device ID Read Methodology
• Low Power Dissipation
– 5 mA Active Read Current (Typical at 20 MHz)
– 5 µA Deep Power-Down Current (Typical)
• Endurance: 100,000 Program/Erase Cycles
• Data Retention: 20 Years
• Complies with Full Industrial Temperature Range
• Industry Standard Green (Pb/Halide-free/RoHS Compliant) Package Options
– 16-Lead SOIC (300-mil wide)
– 8-Contact Very Thin DFN (6 x 8 mm)
敲入如下的测试代码，对FLASH的操作作如下测试：
1、擦除后FLASH内容是0x00还是0xFF ？
2、擦除 - 写入 - 读出，查看数据是否正确写入？
3、不擦除直接写入的情况下，读出数据查看数据是否正确写入？
4、往FLASH的额定地址范围之外写入数据，结果如何？

#define TEST_CASE1
int main(void)
{
   sysclk_init();
   board_init();
   at25dfx_initialize();
   at25dfx_set_mem_active(AT25DFX_MEM_ID);
   at25dfx_protect_chip(AT25_TYPE_UNPROTECT);
   uint8_t array[512];
   uint16_t n;
   for(n = 0;n < 512;n++) {
      array[n] = n;
   }
#if TEST_CASE == 0 // 查看擦除之后的数据
   at25dfx_erase_block(128);
   at25dfx_read(array,512,128);
   asm("nop");
#elif TEST_CASE == 1 // 是否正确写入
   at25dfx_erase_block(128);
   for(n = 0;n < 512;n++) {
   array[n] = n;
   }
   at25dfx_write(array,512,128);
   for(n = 0;n < 512;n++) {
   array[n] = 0;
   }
   at25dfx_read(array,512,128);
   asm("nop");
#elif TEST_CASE == 2// 写入之前不擦除，是否能正确写入
   for(n = 0;n < 512;n++) {
   array[n] = n;
   }
   at25dfx_write(array,512,128);
   for(n = 0;n < 512;n++) {
   array[n] = 0;
   }
   at25dfx_read(array,512,128);
   asm("nop");
#elif TEST_CASE == 3 // 往FLASH地址范围之外写
   at25dfx_erase_block(128);
   for(n = 0;n < 512;n++) {
   array[n] = n;
   }
   at25dfx_write(array,512,0x7FFFFF);
   for(n = 0;n < 512;n++) {
   array[n] = 0;
   }
   at25dfx_read(array,512,0x7FFFFF);
   asm("nop");
#else
#endif




总结：
1、AT25DF64擦除之后数据为0xFF
2、AT25DF64在往某个地址写入数据前，必须执行擦除操作，否则不能正确写入
3、往AT25DF64额定地址之外的地址写入数据，将出错
4、AT25DF64的最大地址为0x7FFFFF,容量8Mbyte