M37270MF Datasheet, PDF (29/94 Pages) Mitsubishi Electric Semiconductor – SINGLE-CHIP 8-BIT CMOS MICROCOMPUTER with CLOSED CAPTION DECODER and ON-SCREEN DISPLAY CONTROLLER

MITSUBISHI MICROCOMPUTERS
M37270MF-XXXSP
M37270EF-XXXSP, M37270EFSP
SINGLE-CHIP 8-BIT CMOS MICROCOMPUTER with CLOSED CAPTION DECODER
and ON-SCREEN DISPLAY CONTROLLER
(4) Timing Signal Generating Circuit
This circuit generates a reference clock which is 832 times as large
as the horizontal synchronizing signal frequency. It also generates
various timing signals on the basis of the reference clock, horizontal
synchronizing signal and vertical synchronizing signal. The circuit
operates by setting bit 0 of data slicer control register 2 (address
00EB16) to “1.”
The reference clock can be used as a display clock for OSD function
in addition to the data slicer. The HSYNC signal can be used as a
count source instead of the composite sync signal. However, when
the HSYNC signal is selected, the data slicer cannot be used. A count
source of the reference clock can be selected by bit 1 of data slicer
control register 2 (address 00EB16).
Composite
sync signal
V-pulse
(“L” pulse width is long,
“H” pulse width is short)
Bit 5 of
DSC2
0
1
1
AB
Fig. 23. Determination of V-pulse waveform
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