External programming of at least one processor (30) of a LED driver (10). In a normal operation mode a first control input (22B/22C) of the LED driver (10) may be provided to a first processor input of the processor and a second control input (22B/22C) of the LED driver may be provided to a second processor input of the processor (30). In a programming mode the first and second control inputs (22B, 22C) may be provided to programming inputs of the processor (30) to thereby enable programming of the processor (30) via the first and second control inputs (22B, 22C).