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37
SINGLE-CHIP 8-BIT CMOS MICROCOMPUTER with CLOSED CAPTION DECODER
and ON-SCREEN DISPLAY CONTROLLER
M37274MA-XXXSP
PRELIMINARY
Notice: This is not a final specification.
Some paramentic limits are subject to change.
MITSUBISHI MICROCOMPUTERS
Selection of field to be sliced data
In the case of the main data slice line, the field to be sliced data is
selected by bits 2 and 1 of the data slicer control register 1 (address
00EA
16
). In the case of the sub-data slice line, the field is selected
by bits 2 and 1 of the data slicer control register 3. When bit 2 of
the data slicer control register 1 is set to “1,” it is possible to slice
data of both fields (refer to Figure 26).
Specification of line to set slice voltage
The reference voltage for slicing (slice voltage) is generated by
integrating the amplitude of the clock run-in pulse in the particular
line (refer to Table 4).
Field determination
The field determination flag can be read out by bit 5 of the data
slicer control register 1. This flag charge at the falling edge of
V
sep
.
Fig. 30. Signals in Vertical Blanking Interval
(5) Data Slice Line Specification Circuit
Specification of data slice line
M37274MA-XXXSP has 2 data slice line specification circuits for
slicing arbitrary 2 H
sep
in 1 field. The following 2 data slice lines
are specified .
<Main data slice line>
This line is specified by the caption position register (address
00E0
16
).
<Sub-data slice line>
This line is specified by the data slicer control register 3 (address
00EB
16
).
The counter is reset at the falling edge of V
sep
and is incremented
by 1 every H
sep
pulse. When the counter value matched the value
specified by bits 4 to 0 of the caption position register (in case of
the sub-data slice line, by bits 3 to 7 of the data slicer control register
3), this H
sep
is sliced.
The values of “00
16
” to “1F
16
” can be set in the caption position
register. Bit 7 to bit 5 are used for testing. Set “100
2
.” Figure 30
shows the signals in the vertical blanking interval. Figure 31 shows
the structure of the caption position register.
Line
Line specified by bits 4 to 0 of CP
(Main data slice line)
Line specified by bits 7 to 3 of DSC3
(Sub-data slice line)
Table 4. Specifying of Field Whose Sets Reference Voltage
Bit 0 of DSC3
DSC1 : Data slice control register 1
DSC3 : Data slice control register 3
CP : Caption position register
Field
Field specified by bit 1 of DSC1
0: F2
1: F1
Field specified by bit 1 of DSC3
0: F2
1: F1
0
1
Video signal
Vertical blanking interval
Composite
video signal
Count value to be set in the caption position register (“11
16
” in this case)
H
sep
V
sep
H
sep
Magnified
drawing
Clock run-in
Start bit + 16-bit data
Start bit
Time to be set in the
start bit position register
Composite video
signal
min. max.
Line 21