To effectively program AVR based microcontroller you must have knowledge about its memory space. Since there is not just one memory space. There are three different address spaces. They are:
- Data memory (SRAM)
Here all your the intermediate results are stored and all the run time calculation get carried in this memory space. - Program memory
It is the memory where your application code is stored. And also it stores the constants. It could be divided into two sections by setting appropriate fuse bits. The two section will be:- Application Section
- Boot Section
- EEPROM
This is the memory where you can save the run time data such as configuration options, intermediate result for future processing. But it is very limited in size. So proper managment had to be taken care. Since it limits the size of certain applications.
Out of the three memories present in the ATmega16a, only the SRAM is volatile.
Size and address of memory space
- Data Memory
1024 Bytes (Starting Address: 0x0060 – Last Address: 0x045F)
96 Address which contain two section General purpose Register and I/O Registers.
General Purpose Register ( Starting Address: 0x0000 – Last address: 0x001F)
I/O register (Starting Address: 0x0020 – Last address: 0x005F) - Program Memory
Flash Type memory organised into 8000 memory location each pointing to a 16 bit wide data.
Starting Address: 0x0000
Last Address: 0x1FFF
NOTE: Care must be taken while Read/Write operations of EEPROM. It is very sensitive to operating conditions. Variations outside the tolerance limits could result in corruption of data in the worst case total loss of stored data. It is highly recommended that a stable power source must be used if performing frequent EEPROM operations.
