Only the function's data is stored on the stack; its code stays in flash. You can't really save any SRAM by using EEPROM because, as you have seen, EEPROM isn't addressable in the same way. The code to read and store EEPROM also needs to use some SRAM - probably as much SRAM as you were trying to save! EEPROM is also slow to write, and has a limited lifetime (in number of writes to each byte), both of which make it impractical to use for storing the kind of temporary data we usually put on the stack. It is better suited to saving infrequently changed data, like the unique device configuration for mass-produced devices, or capturing infrequent errors for later analysis.

Edited:

  What really happens after the function returns is that its stack-frame (its reserved area of SRAM) is no longer reserved. It will eventually be re-used by another function call. Here is a diagram of a C stack in memory. When a stack frame is no longer useful, it is simply abandoned and its memory becomes available to be re-used.

Only the function's data is stored on the stack; its code stays in flash. You can't really reduce SRAM use by using EEPROM instead because, as you have seen, EEPROM isn't addressable in the same way. The code to read and store EEPROM also needs to use some SRAM - probably as much SRAM as you were trying to save! EEPROM is also slow to write, and has a limited lifetime (in number of writes to each byte), both of which make it impractical to use for storing the kind of temporary data we usually put on the stack. It is better suited to saving infrequently changed data, like the unique device configuration for mass-produced devices, or capturing infrequent errors for later analysis.

Edited: There is no stack for that function until the function has been called, so yes, that is when any of the function's data get's put there. What happens after the function returns is that its stack-frame (its reserved area of SRAM) is no longer reserved. It will eventually be re-used by another function call. Here is a diagram of a C stack in memory. When a stack frame is no longer useful, it is simply released and its memory becomes available to be re-used.

Only the function's data is stored on the stack; its code stays in flash. You can't really save any SRAM by using EEPROM because, as you have seen, EEPROM isn't addressable in the same way. The code to read and store EEPROM also needs to use some SRAM - probably as much SRAM as you were trying to save! EEPROM is also slow to write, and has a limited lifetime (in number of writes to each byte), both of which make it impractical to use for storing the kind of temporary data we usually put on the stack. It is better suited to saving infrequently changed data, like the unique device configuration for mass-produced devices, or capturing infrequent errors for later analysis.

Only the function's data is stored on the stack; its code stays in flash. You can't really save any SRAM by using EEPROM because, as you have seen, EEPROM isn't addressable in the same way. The code to read and store EEPROM also needs to use some SRAM - probably as much SRAM as you were trying to save! EEPROM is also slow to write, and has a limited lifetime (in number of writes to each byte), both of which make it impractical to use for storing the kind of temporary data we usually put on the stack. It is better suited to saving infrequently changed data, like the unique device configuration for mass-produced devices, or capturing infrequent errors for later analysis.

Edited:

What really happens after the function returns is that its stack-frame (its reserved area of SRAM) is no longer reserved. It will eventually be re-used by another function call. Here is a diagram of a C stack in memory. When a stack frame is no longer useful, it is simply abandoned and its memory becomes available to be re-used.