xLIW - a scaleable long instruction word [DSP applications]

Increasing system complexity of SOC applications leads to an increasing requirement of powerful embedded DSP processors. To increase the computational power of DSP processors, the number of pipeline stages has been increased for higher frequencies and the number of parallel executed instructions, to increase the computational bandwidth. To program the parallel units, the VLIW (very long instruction word) has been introduced. Programming the parallel units at the same time leads to an expanded program memory port or to the limitation that only a few units can be used in parallel. To overcome this limitation, this paper proposes a scaleable long instruction word (xLIW). The xLIW concept allows the full usage of the available units in parallel with optimal code density. An instruction buffer included reduces the power dissipation at the program memory ports during loop handling. The xLIW concept is part of a development project of a configurable DSP.