Friday, 27 November 2009 03:41
M. Ganesh Raaja
Questions:
1. I would like to place a constant variable in an absolute address in Flash. I will place information like version and serial number in this absolute address. How do I do this?
2. I would like to place a function in an absolute address in Flash. How do I do this?
Answer: You can place either a constant variable or a function in absolute address in flash using the #pragma abs_address directive.
For example, to place constant variables in absolute address 0x3FC0:
#pragma abs_address 0x3FC0
const BYTE Version = 0x01; // This byte is placed in address 0x3FC0
const char SerialNumber[] = "1234567890"; // This string is placed from address 0x3FC1
#pragma end_abs_address
To place a function "MyFunction" at address 0x1000, the same approach may be used.
#pragma abs_address 0x1000
void MyFunction(void)
{
// Function code here
}
#pragma end_abs_address
Friday, 27 November 2009 02:29
Madhan Kumar K
Question: How do I place a RAM variable in an absolute RAM address?
Answer: A RAM variable may be placed in an absolute RAM address using three methods.
Option-A: Using the #pragma directive
Let us say, we need to allocate a variable ‘myByte’ at an address 0x78 in RAM and another variable ‘myByte1’ at address 0x104 , then the process would be:
Read more...
