SDRAM STM32F429 refresh problem

[m_]

Posted on July 04, 2014 at 13:58The original post was too long to process during our migration. Please click on the attachment to read the original post.

[h239955]

Posted on June 03, 2015 at 15:31

Clarification of original symptoms

This is not a refresh problem. This immediate readback of a write like Michel's test below gives the expected value for 'number2' even with the SDRAM device physically removed from the board! It took me ages to find that out. In my case the software turned out to be correct but the RAM device wasn't soldered down properly. Michel's test:

    //We declarate a variable test as a float in the SDRAM

    __attribute__((section(''.sdram_data''))) float test;    //Just some numbers    float number1 = 12.5, number2;    int main(void)    {        test = number1;        number2 = test;    }