Posted on May 17, 2011 at 13:35Hi,
I am using a STM3210E-EVAL board in combination with Keil and an Ulink2.
I am trying to use the FSMC in combination with the SRAM on the board.
I studied the SRAM example program from STM. Works perfect.
I will be using the SRAM as a data buffer. I read sample data from an ADC and store these values in the SRAM. This happens in an interrupt. In another interrupt I read data from the SRAM.
Interrupt are configured with different priority. I use the NVIC_SETPRIMASK(); and RESET when reading, so the writing cant interrupt the read process.
My problem is that I read wrong values from the SRAM! The memory of the SRAM you can see in Keil, here all data is correct! So reading from the SRAM goes wrong!
I have to read and write fast after each other, and I think here goes something wrong. Although i don't know what.
Down here is a piece of code that gives the same wrong data as my actual program.
Am I doing anything wrong or do I have to do anything between writes and reads?
FSMC setup code is the same as the example program.
Hope someone can point me in the right direction!
Code:
for (i=0; i<=1000;i++)
{
num_samples++;
FSMC_SRAM_WriteBuffer(&num_samples, adc_data_write_pointer + ch_write_offset, 2);
FSMC_SRAM_ReadBuffer(&lees, adc_data_write_pointer + ch_write_offset, 2);
if (num_samples != lees) /*to see what values are wrong*/
{
help0=num_samples;
help1=lees;
help2= adc_data_write_pointer;
help3= ch_write_offset;
help4++;
hulp5[help4] = help0;
}
if (num_samples == 0x200)
{
help0++; /* i put my breakpoint here */
}
ch_write_offset += 4;
if (ch_write_offset == 32)
{
ch_write_offset = 0;
adc_data_write_pointer += 32;
}
}
