I have a question on reading data from flash.
Should I write
FCTL1 = FRKEY;
before I read data from flash?
The below is my program. This works without problem.
When I write data to flash, I set FCTL1 = FWKEY;
Then, I read data from flash. But when I set FCTL1 = FRKEY;
the program stops.
Is the FCTL1 automatically cleared for reading?
I use msp430F2112.
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#include "msp430x21x2.h"
union uFlashData {
float fval;
char cval[9];
} g_flashVal;
// Function prototypes
void read_SegC();
void write_SegC();
void main(void)
{
WDTCTL = WDTPW + WDTHOLD; // Stop watchdog timer
if (CALBC1_1MHZ ==0xFF || CALDCO_1MHZ == 0xFF)
{
while(1); // If calibration constants erased
// do not load, trap CPU!!
}
// Init for Flash Writing
BCSCTL1 = CALBC1_1MHZ; // Set DCO to 1MHz
DCOCTL = CALDCO_1MHZ;
FCTL2 = FWKEY + FSSEL0 + FN1; // MCLK/3 for Flash Timing Generator
TA0CCR0 = 50000;
TA0CTL = TASSEL_2 + MC_1; // SMCLK, upmode
__enable_interrupt(); // enable interrupts
g_flashVal.fval = 3.14159265;
write_SegC();
g_flashVal.fval = 0.0;
read_SegC(); // Write segment C, increment value
__no_operation(); // SET BREAKPOINT HERE
}
void write_SegC()
{
char *Flash_ptr; // Flash pointer
unsigned int i;
Flash_ptr = (char *)0x1040; // Initialize Flash pointer
FCTL3 = FWKEY; // Clear Lock bit
FCTL1 = FWKEY + ERASE + EEI; // Set Erase bit, allow interrupts
*Flash_ptr = 0; // Dummy write to erase Flash seg
FCTL1 = FWKEY + WRT; // Set WRT bit for write operation
for (i = 0; i < 4; i++)
{
*Flash_ptr++ = g_flashVal.cval[i]; // Write value to flash
}
FCTL1 = FWKEY; // Clear WRT bit
FCTL3 = FWKEY + LOCK; // Set LOCK bit
}
void read_SegC()
{
char *Flash_ptr; // Flash pointer
unsigned int i;
Flash_ptr = (char *)0x1040; // Initialize Flash pointer
for (i = 0; i < 4; i++)
{
g_flashVal.cval[i] = *Flash_ptr++; // Read value from flash
_NOP();
}
}
