Data signal control oscillator for video display

摘要

The free running frequency of the bus control horizontal oscillator 31 is controlled by a first data signal D6US coupled to a digital to analogue converter 40 via a first digital to analogue converter 41, The data signal DATA1 may change the oscillator free running frequency to provide tolerance compensation. The second data signal is independent of data error. The first data signal is not related to data error but can only change the oscillator frequency within a relatively narrow range. Thus, a data error would not cause a significant change in the oscillator free running frequency if both data signals were both variable.