Zilog Z8F0130 - Manual (Page 270)

Using the ANSI C-Compiler UM013037-1212
246
Zilog Developer Studio II – Z8 Encore!
User Manual
•
If you do not have any initialized global or static variables in far memory, the start-up
code does not have to set the initialized global and static far variables to their initial
value from ROM.
As an example, for the small model:
far int val = 20; // Not OK to skip initializing far data:

// Initialized global in far memory

int val = 20; // OK to skip initializing far data:

// Initialized global in near memory
For the large model:
int val = 20; // Not OK to skip initializing far data:

// Initialized global in far memory

near int val = 20; // OK to skip initializing far data:

// Initialized global in near memory
Alternatively, if your application does require global or static variables in far memory
to have initialized values and you perform the initialization in your program as part of
the code, the start-up code does not have to perform this function.
For example:
far int val;

void main (void)

{

val = 20; // Initialization performed as part of the code

}
This can be achieved by adding the following code just before segment startup :
COPYERAM SET FALSE
•
For the Z8 Encore! 16K XP Series CPUs, if you do not have any code in PRAM, the
start-up code does not have to copy the PRAM code from ROM to its PRAM location.
This can be achieved by adding the following code just before segment startup :
COPYPRAM SET FALSE

For Z8 Encore! microcontroller devices with small Flash memory sizes especially, the pre-
ceding steps can be very useful to reduce the code size of the C start-up module.
Segment Naming
The compiler places code and data into separate segments in the object file. The different
segments used by the compiler are listed in the following table.