- SS-HQ1 Application Notes -
Ver.1.0.0 January 7, 2005
54
The
shows luminance signal processing with the NTSC form and relations with the standard output
level of Y-DAC.
SS-HQ1 system sets up the standard output level of the luminance signal (with gamma processing) as
NTSC-100[IRE] when an A/D input level is the standard 400[mV]. And Sync-level as NTSC=-40[IRE] is added,
too.
Therefore,
The standard output level (Y-DAC) = 70[%] / full scale 100[%].
The Sync-level (Y-DAC) = 20[%] / full scale 100[%].
--- Parameter reference (the luminance signal, NTSC standard setting) ---
(CAT1_Byte5_bit0-4) SYNCLV = 9[h] (Sync-level as -40[IRE])
(CAT2_Byte7_bit2-4) YGAMSEL= 4[h]
(CAT2_Byte7_bit5-7) YKNEESEL = 3[h]
(CAT2_Byte8_bit0-7) YGAIN = 80[h]
(CAT2_Byte10_bit0-5) SETUP = C[h] (7.5[IRE])
When an A/D input level is the maximum 1000[mV] (=250[%]), Y-DAC outputs the full scale as NTSC=160
[IRE] (the luminance signal with gamma processing).
The built-in Y-DAC is controllable by reference voltage (VREFY). The output of Y-DAC is the current-flow type
and must be converted to voltage level by the terminal-resistance 200[ohm].
See “3.9 DAC Mode and YC-mix External Analog Circuit” of “3.Peripheral Circuits”, for internal Y-DAC
peripheral circuit examples and usage notes.
The chrominance signal is not discussed here because it differs according to the spectral characteristics of the
CCD image sensor and the imaged subject. And its standard level cannot be defined.
--- Parameter reference (the chrominance signal, NTSC standard setting) ---
(CAT1_Byte13_bit0-6) BSTLV = 38[h] (burst-amplitude = 40[IRE])
The chroma signal is output from the internal C-DAC when (CAT1_Byte3_bit2) DACMODE is set to 1[h].
The built-in C-DAC is controllable by reference voltage (VREFC). The output of C-DAC is the current-flow type
and must be converted to voltage level by the terminal-resistance 200[ohm].
See “3.9 DAC Mode and YC-mix External Analog Circuit” of “3.Peripheral Circuits”, for internal C-DAC peripheral
circuit examples and usage notes.
8.1.1.5. In a case of the Composite Output mode
In a case,
(CAT1_Byte3_bit2) DACMODE = 0[h]
This is the composite output mode through the built-in YC-MIX block. The composite signal of luminance and
chrominance (moderated with sub-career) is made in YC-MIX block. And Y-DAC outputs the composite signal.
In this case, C-DAC outputs no signal.
See “3.9 DAC Mode and YC-mix External Analog Circuit” of “3.Peripheral Circuits”, for notes on composite
output mode.