.[.A clock recovery circuit in a digital display unit for recovering a
time reference signal associated with analog display data. The clock
recovery circuit includes a phase-locked loop (PLL) implemented in
digital domain and an analog filter to eliminate any undesirable
frequencies from the output signal of the PLL. The PLL includes
independent control loops to track long term frequency drifts of the time
reference signal and the transient phase differences respectively. By
providing such independent control loops, the generated clock can be
better synchronized with the time reference signal..]. .Iadd.A system and
method for displaying an analog source image by a digital display unit. A
converter circuit generates a plurality of digital source image elements
from an analog source image based upon a sampling clock signal
synchronized with a time reference signal associated with the analog
source image. A scaler unit receives the digital source image elements in
accordance with a first clock signal, scales the source image elements
independently in both vertical and horizontal directions to form
destination image elements, and provides the destination image elements
to the display unit in accordance with a second clock signal. The first
clock signal and the second clock signal are arranged such that a source
frame rate and a destination frame rate are substantially equal..Iaddend.