# Special Considerations with Microchip MPLAB® IDE Tools

The latest versions of Microchip’s software tools have been designed to fully support the extended instruction set on the PIC18 devices. This includes the MPLAB XC8 C compiler, MPASM Assembler and MPLAB X Integrated Development Environment (IDE).

When selecting a target device for software development, MPLAB X IDE will automatically set default Configuration bits for that device. The default setting for the XINST Configuration bit is ‘0’, disabling the extended instruction set and Indexed Literal Offset Addressing mode. For proper execution of applications developed to take advantage of the extended instruction set, XINST must be set during programming.

To develop software for the extended instruction set, the user must enable support for the instructions and the Indexed Addressing mode in their language tool(s). Depending on the environment being used, this may be done in several ways:

• A menu option, or dialog box within the environment, that allows the user to configure the language tool and its settings for the project
• A command-line option
• A directive in the source code

These options vary between different compilers, assemblers and development environments. Users are encouraged to review the documentation accompanying their development systems for the appropriate information.