C251 User's Guide

far

The far memory type may be used for variables and constants. This memory is accessed using 24-bit addresses and may be on-chip or external.

• For variables, far memory is limited to 16M. Objects are limited to 64K and may not cross a 64K boundary (the linker ensures that). Variables declared far are located in the HDATA memory class.
• For constants (ROM variables), far memory is limited to 16M. Objects are limited to 64K and may not cross a 64K boundary (the linker ensures that). Constant variables declared far are located in the HCONST group.

Declare far objects as follows:

unsigned char far far_variable[0x10000];

unsigned char const far far_const_variable[0x4000] =
  { 1, 2, 3, ... };

unsigned int i;

unsigned char far_func (void) {
  return (far_variable[i]);
}