Patent ID: 7739069

Claim:
A test prepared integrated circuit that is switchable to a normal operating mode and a test mode, the test prepared integrated circuit comprising: a test control input for supplying a test control signal to indicate whether the integrated circuit should operate in the normal operating mode or the test mode; a local oscillator circuit with a local oscillator output, the local oscillator output generating an oscillator signal of a predetermined frequency; a mixer circuit having an input and an output; a frequency divider circuit with an input coupled to the local oscillator output, and a frequency divider output and a test input coupled to the test control input, the frequency divider circuit dividing the frequency of the oscillator signal by a predetermined factor; a first multiplexing circuit with signal inputs coupled to the local oscillator output and the frequency divider output and an output coupled to the mixer circuit, the first multiplexing circuit having a control input coupled to the test control input, the multiplexing circuit being arranged to couple the local oscillator output to the input of the mixer circuit in the normal operating mode, and to couple the frequency divider output instead of the local oscillator output to the input of the mixer circuit in the test mode.