An integrated circuit (1600) includes a debug module (1602) and a clock generator (1610). The debug module (1602) is configured to receive a test pattern and provide a mode signal based on the test pattern. The clock generator (1610) includes a first clock input configured to receive a first clock signal, a second clock input configured to receive a second clock signal, and a mode input configured to receive the mode signal. The first and second clock signals are out of phase and have the same clock frequency. The clock generator (1610) is configured to provide a generated clock signal whose effective frequency is based on the first and second clock signals and the mode signal.