Upgrading Nios Software - external flash

code for erasing flash sector

void EraseFlashSector(unsigned int offset)

{

unsigned char i = 0;

volatile char * CommandSeq1 = (char*)(FLASHCTRL_BASE + 0xaaa);

*CommandSeq1 = 0xaa;

volatile char * CommandSeq2 = (char*)(FLASHCTRL_BASE + 0x555);

*CommandSeq2 = 0x55;

volatile char * CommandSeq3 = (char*)(FLASHCTRL_BASE + 0xaaa);

*CommandSeq3 = 0x80;

volatile char * CommandSeq4 = (char*)(FLASHCTRL_BASE + 0xaaa);

*CommandSeq4 = 0xaa;

volatile char * CommandSeq5 = (char*)(FLASHCTRL_BASE + 0x555);

*CommandSeq5 = 0x55;

volatile char * CommandSeq6 = (char*)(FLASHCTRL_BASE + offset);

*CommandSeq6 = 0x30;

// wait for erase completion

while(*CommandSeq6 != 0xffffffff){}

}