TM4C123 , set a variable to specific SRAM memory location.

Raj Patel

I am wondering how could one set a particular variable to a specific internal SRAM location on the TM4C123.

I have a bootloader at vector address of 0x00 that will jump to a particular Flash address. Lets say the flag is a char variable. The bootloader needs to reset a flag variable in SRAM to 0xAB. Next , the bootloader jumps to the test program. The test program needs set the flag to 0xFF.

I want to set flag to SRAM memory of 0x207FFC on both bootloader program and the test program.

over 9 years ago

0 Amit Ashara over 9 years ago

TI__Guru**** 244400 points

Hello Raj

First of all you would need to make sure that the SRAM address is not "corrupted" by code execution. If that is the ensured then you declare

static volatile uint8_t *g_pui8MyVar ;

g_pui8MyVar = (uint8_t *)0x20007FFC;

g_pui8MyVar[0] = Value

Or another way could be to use EEPROM which is outside of the SRAM space and is a NVM memory.

Regards
Amit

0 Raj Patel over 9 years ago in reply to Amit Ashara

Prodigy 120 points

Amit;

Thank you. Everything now works .

Raj

0 Amit Ashara over 9 years ago in reply to Raj Patel

TI__Guru**** 244400 points

Hello Raj

Are you using a SRAM variable or did you use the suggested EEPROM method?

Regards
Amit

0 Raj Patel over 9 years ago in reply to Amit Ashara

Prodigy 120 points

I am using the SRAM variable. On power restart the variable gets reset to 0xE. The bootloader sets the variable to 0xAB. Then the test program sets it back 0xE. I am using 72 percent of the SRAM in the test program . I decided on using memory location 0x20007FCC since it's at the vary end.

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TM4C123 , set a variable to specific SRAM memory location.