MITSUBISHI MICROCOMPUTERS
M37274EFSP
SINGLE-CHIP 8-BIT CMOS MICROCOMPUTER with CLOSED CAPTION DECODER
and ON-SCREEN DISPLAY CONTROLLER
Table 4. Specifying of Field Whose Sets Reference Voltage
Bit 0 of DSC3
0
Field
Line
Line specified by bits 4 to 0 of CP
(Main data slice line)
Field specified by bit 1 of DSC1
Field specified by bit 1 of DSC3
0: F2 1: F1
0: F2 1: F1
Line specified by bits 7 to 3 of DSC3
(Sub-data slice line)
1
DSC1 : Data slice control register 1
DSC3 : Data slice control register 3
CP : Caption position register
(6) Reference Voltage Generating Circuit and
Comparator
slice line specification circuit. Connect a capacitor between the
VHOLD pin and the VSS pin, and make the length of wiring as short
as possible so that a leakage current may not be generated.
Comparator
The composite video signal clamped by the clamping circuit is input
to the reference voltage generating circuit and the comparator.
2
1
Reference voltage generating circuit
The comparator compares the voltage of the composite video signal
with the voltage (reference voltage) generated in the reference
voltage generating circuit, and converts the composite video signal
into a digital value.
This circuit generates a reference voltage (slice voltage) by using
the amplitude of the clock run-in pulse in line specified by the data
Caption Position Register
b7 b6 b5 b4 b3 b2 b1 b0
1
0
0
Caption Position Register (CP) [Address 00E016
]
R
R
W
W
B
Name
Functions
After reset
0
0
to
4
Specification main data
slice line (CP0 to CP4)
W
W
5, 6
0
0
R
R
Fix these bits to “0.”
Fix this bit to “0.”
7
Fig. 39. Caption Position Register
44
RENESAS [ RENESAS TECHNOLOGY CORP ]
