In the example described, the dynamic shared RAM (75) in the software-defined communication system, store program code in the flash memory (71), and a part of the code is when copied to a section of RAM, then according to whether it is necessary to be performed during the first state of the TX state machine, and another part of the code is adapted after how the same sections, depending on whether may be performed during subsequent second state code to include that category into groups of transmission category. Similarly, some of the code is always copied to the section of the RAM, according to whether it is necessary to be performed during the first state subsequent RX state machine, and how the different parts of the code in this section is adapted after, depending on whether subsequently may be performed during the second state of the RX state machine, with portions of the code is categorized into groups of receiving category, the amount of RAM is reduced without sacrificing speed performance that.