Rev. 1.0, 02/00, page 766 of 1141
Bit 5
V Complement and Mask Counter Clock Source Select (VCKSL): Selects the clock
source for the V complement and mask counter: double the frequency of the horizontal sync signal
for the AFC (AFCH signal) or that for the H complement and mask counter (OSCH signal). When
the text display mode is selected for the OSD and internally generated Hsync signal is selected as
the reference Hsync signal for the AFC by setting the HSEL bit (bit 5) of the SEPACR, setting this
VCKSL bit to 1 enables the external Vsync signal to be detected irrespectively of the text display
mode operation.
Bit 5
VCKSL
Description
0
Double the frequency of the horizontal sync signal (AFCH signal) for the AFC
(Initial value)
1
Double the frequency of the horizontal sync signal (OSCH signal) for the H
complement and mask counter
Bit 4
V Complement Function Control (VCMPON): Enables or disables the V complement
function of the V complement and mask counter. The V complement function prevents the Vsync
detection being delayed and missed in a weak field. For the timing, refer to section 27.2.5, Vertical
Sync Signal Threshold Register (VVTHR).
Bit 4
VCMPON
Description
0
The V complement function is disabled
(Initial value)
1
The V complement function is enabled
Bit 3
Internal Csync Generator Clock Source Select (HCKSEL): Selects the clock source for
the internal Csync generator: the 4/2 fsc clock or the AFC reference clock. When the text display
mode is selected for the OSD and the external Hsync signal is selected as the reference Hsync
signal for the AFC, set this HCKSEL bit to 1 to generate the internal Csync signal from the AFC
reference clock. In this case, however, the Hsync and Vsync signals must be dedicated separation
inputs, with both signals having equal cycles and pulse widths. When setting the HCKSEL bit to
1, clear the FRQSEL bit and set the AFC circuit reference clock frequency to 576 times the
horizontal cycle signal. Note that the OSD module will not operate if the HCKSEL bit and
FRQSEL bit are both set to 1.
Bit 3
HCKSEL
Description
0
4/2 fsc clock
(Initial value)
1
AFC reference clock