1. An integrated circuit comprising: processing logic configured to execute a program; watchpoint monitoring logic configured to review values of one or more signals occurring within the integrated circuit as a result of execution of said program, the watchpoint monitoring logic comprising: a storage element for storing configuration data; an interface via which the configuration data is software programmable having regard to a set of watchpoint values of said one or more signals to be monitored; and hash logic configured for a value to be reviewed to perform a hash operation on that reviewed value in order to reference the configuration data to determine whether that reviewed value is either definitely not a value within said set of watchpoint values or is potentially a value within said set of watchpoint values; the watchpoint monitoring logic being configured to generate a trigger signal if it is determined that that reviewed value is potentially a value within said set of watchpoint values, the trigger signal being used to trigger a further monitoring process, wherein the trigger signal is used to trigger as at least part of said further monitoring process a checking operation to determine whether the reviewed value causing the trigger signal to be generated is a value within said set of watchpoint values; and if a number of watchpoint values in said set of watchpoint values is increased, the configuration data being reprogrammed via the interface without increasing the size of the storage element.