These variable attributes are available for H8/300 targets:
eightbit_data ¶Use this attribute on the H8/300, H8/300H, and H8S to indicate that the specified variable should be placed into the eight-bit data section. The compiler generates more efficient code for certain operations on data in the eight-bit data area. Note the eight-bit data area is limited to 256 bytes of data.
You must use GAS and GLD from GNU binutils version 2.7 or later for this attribute to work correctly.
tiny_data ¶Use this attribute on the H8/300H and H8S to indicate that the specified variable should be placed into the tiny data section. The compiler generates more efficient code for loads and stores on data in the tiny data section. Note the tiny data area is limited to slightly under 32KB of data.