1. A method of checking the resistance of a programmable element in an integrated circuit, comprising the steps of: producing a first voltage at a first node based on the resistance of a programmable element; producing a second voltage at a second node based on a known resistance; and comparing said first and second voltages and producing an output signal in response to said comparison, the binary value of said output signal indicating whether the resistance of the programmable element is higher or lower than the known resistance.