1. A data processing system comprising: a low density parity check decoder comprising a variable node processor, a check node processor and a scaler circuit, wherein the low density parity check decoder is operable to scale soft information with a scaling factor in the scaler circuit while iteratively generating and processing check node to variable node messages in the variable node processor and variable node to check node messages in the check node processor between a plurality of check nodes and variable nodes, wherein the scaling factor is derived from a distribution of possible values in an input to the low density parity check decoder.