4.3.10.1 Absdata Attribute

The absdata attribute indicates that the objects can be accessed by the lds and sts instructions, which take absolute addresses. This attribute is only supported for the reduced tinyAVR core, for example the ATtiny40 device.

You must make sure that respective data is located in the address range 0x40-0xbf to prevent out of range errors. One way to achieve this as an appropriate linker description file.