ML6430/ML6431
FUNCTIONAL DESCRIPTION (Continued)
Audio Clock: The Ml6430/ML6431 outputs a clock at
32kHz, 44.1kHz, or 48kHz. This clock is locked in
frequency to the basic video clock regardless of the
standard being used. With VCR head switches, the phase
correction required to track the timing is removed from
the audio clock by a patented circuit. This prevents the
audio clock from being modulated by step changes in
video timing. See the Table 9 for the audio clock rates
supported and how they are derived internally.
This bit controls the source of AUDIOCLK/PHERROUT.
When this bit is low, AUDIOCLK/PHERROUT provides the
audio clock output. When this bit is high, AUDIOCLK/
PHERROUT provides the 1-bit digital phase error of each
Hsync edge.
Additionally, when both PHERROUT enable and VGA bits
are logic high, the reset point of the pixel counter is
changed from 512 to 256. This changes the equation for
calculating the number of pixels per line verses the Pixel
Counter bits to the following:
ADDITIONAL CONTROL REGISTERS (ML6431 ONLY)
DisAutoVCR: Disables the auto VCR detect circuit.
Register 7, Bit 0: DisAutoVCR
P[10:0] = 2 ´ (number of pixels per line) – 512
(2)
PHERROUT:
MUX phase error signal onto
AUDIOCLK/PHERROUT pin.
Register 7, Bit 3: PHERROUT enable
VIDEOSTANDARD
AUDIO RATE
AUDIO/PIXEL CLOCK RATIO
AUDIO/FRAME RATE RATIO
CCIR601 NTSC
CCIR601 NTSC
CCIR601 NTSC
48kHz
44.1kHz
32kHz
(96000 ÷ 27MHz) ´ 13.5MHz
(88200 ÷ 27MHz) ´ 13.5MHz
(64000 ÷ 27MHz) ´ 13.5MHz
(8008 ÷ 5) ´ 29.97Hz
(147147 ÷ 100) ´ 29.97Hz
(16016 ÷ 15) ´ 29.97Hz
CCIR601 PAL
CCIR601 PAL
CCIR601 PAL
48kHz
44.1kHz
32kHz
(96000 ÷ 27MHz) ´ 13.5MHz
(88200 ÷ 27MHz) ´ 13.5MHz
(64000 ÷ 27MHz) ´ 13.5MHz
(1920) ´ 25Hz
(1764) ´ 25Hz
(1280) ´ 25Hz
NTSC Square Pixel
NTSC Square Pixel
NTSC Square Pixel
48kHz
44.1kHz
32kHz
(105600 ÷ 27MHz) ´ 12.27MHz
(97020 ÷ 27MHz) ´ 12.27MHz
(70400 ÷ 27MHz) ´ 12.27MHz
(8008 ÷ 5) ´ 29.97Hz
(147147 ÷ 100) ´ 29.97Hz
(16016 ÷ 15) ´ 29.97Hz
PAL Square Pixel
PAL Square Pixel
PAL Square Pixel
48kHz
44.1kHz
32kHz
(96000 ÷ 29.5MHz) ´ 14.75MHz
(88200 ÷ 29.5MHz) ´ 14.75MHz
(64000 ÷ 29.5MHz) ´ 14.75MHz
(1920) ´ 25Hz
(1764) ´ 25Hz
(1280) ´ 25Hz
NTSC 4xFSC
NTSC 4xFSC
NTSC 4xFSC
48kHz
44.1kHz
32kHz
(105600 ÷ 31.5MHz) ´ 14.32MHz
(92400 ÷ 30MHz) ´ 14.32MHz
(70400 ÷ 31.5MHz) ´ 14.32MHz
(8008 ÷ 5) ´ 29.97Hz
(147147 ÷ 100) ´ 29.97Hz
(16016 ÷ 15) ´ 29.97Hz
PAL 4xFSC
PAL 4xFSC
PAL 4xFSC
48kHz
44.1kHz
32kHz
(76800 ÷ 28.37MHz) ´ 17.72MHz
(70560 ÷ 28.37MHz) ´ 17.72MHz
(51200 ÷ 28.37MHz) ´ 17.72MHz
(1920) ´ 25Hz
(1764) ´ 25Hz
(1280) ´ 25Hz
Table 9. Audio Clock Generation (ML6430/ML6431)
17
MICRO-LINEAR [ MICRO LINEAR CORPORATION ]
