1. A configurable execution unit ( 126 ) comprising: operator modules ( 202 - 208 ) capable of being dynamically configured at the level of processing multi-bit operand values by a data processing instruction, the or each operator module being connectable to receive input operands indicated in the data processing instruction, wherein at least one configurable operator module is dynamically configurable by operator configuration settings to adjust operator function and/or behavior within said general operation class characterized in that at least one configurable operator module is hard-wired to support a predetermined class of operation; and characterized by a programmable lookup table ( 210 ) implemented as a programmable logic array connectable to receive (i) dynamic configuration information ( 277 ) determined from an opcode portion of the data processing instruction, the programmable lookup table comprising pseudo static control information ( 249 ) provided independently of the data processing instruction carrying the dynamic configuration information and the programmable logic array further connectable to receive (ii) one or more control output(s) ( 281 ) from the operator modules and operable to translate the dynamic configuration information with the control output(s) ( 281 ) into the operator configuration settings ( 279 ) defining an aspect of the function and/or behavior of said configurable operator module for dynamically configuring the operator modules on an instruction-by-instruction basis; and a configurable switch fabric ( 240 , 250 ) connected to provide said input operands to the operator modules and having connectivity defined at least in part by pseudo static control information ( 249 ) provided independently of the data processing instruction carrying the dynamic configuration information.