Posted on May 17, 2011 at 09:33 I have a Keil MCBSTR912 board and a REVA STR912 board and am having the same problem on both.
I hook a battery to the processor VBATT pin, and remove the power from the board. When you hook power back up, it reboots and clears the memory variables when I think it shouldn't.
So it doesn't look like the VBATT SRAM thing is working. Any suggestions ??
#include ''91x_lib.h''
#include ''main.h''
GPIO_InitTypeDef GPIO_InitStructure;
static unsigned char display_byte;
static int delaycnt;
int main()
{
// //////////////////////////////////////////////////////////////////////////////////////////////////////
SCU_APBPeriphClockConfig(__GPIO7, ENABLE);
// GPIO7 goes to the LEDs
GPIO_DeInit(GPIO7);
GPIO_StructInit(&GPIO_InitStructure);
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_All;
GPIO_InitStructure.GPIO_Direction = GPIO_PinOutput;
GPIO_InitStructure.GPIO_Type = GPIO_Type_PushPull;
GPIO_InitStructure.GPIO_IPConnected = GPIO_IPConnected_Disable;
GPIO_InitStructure.GPIO_Alternate = GPIO_OutputAlt1;
GPIO_Init(GPIO7, &GPIO_InitStructure);
// //////////////////////////////////////////////////////////////////////////////////////////////////////
SCU_APBPeriphClockConfig(__RTC,ENABLE);
RTC_DeInit();
RTC_SRAMBattPowerCmd(ENABLE);
// //////////////////////////////////////////////////////////////////////////////////////////////////////
while (1)
{
for (delaycnt = 0; delaycnt < 500000; delaycnt++); // sleep
GPIO_Write(GPIO7, display_byte++);
}
}
