The MK1573 GenClockTM provides genlock timing for video overlay systems. The device accepts the horizontal sync (HSYNC) signal as the input reference clock, and generates a frequencylocked high speed output. Stored in the device are the multipliers for 16 combinations of popular frequencies for analog and digital TV and set-top box systems. Frequency-locked outputs include 1X, 4X, and 8X the subcarrier frequencies of NTSC and PAL systems, and 27MHz plus 13.5MHz for digital video systems. In most selections, the chip recovers the HSYNC clock by outputting a low jitter 50% duty cycle version of HSYNC. Also available is an inverted recovered HSYNC clock, and a double speed recovered HSYNC clock.