cx25840 Conexant Systems, Inc., cx25840 Datasheet - Page 224

• Manufacturer Part Number: cx25840
• Description: Video Decoder And Broadcast Audio
• Manufacturer: Conexant Systems, Inc.

Register Map
5-82
VBI Custom 3 Slice Distance
[7:4]
[3:0]
VBI Custom 3 Clock Run-in Window
[7]
[6:0]
VBI Custom 3 Frame Code Low
[7:0]
VBI Custom 3 Frame Code Mid
[7:0]
VBI Custom 3 Frame Code High
[7:0]
Bits
Bits
Bits
Bits
Bits
RW
Type
RW
RW
RZ
RW
RW
RW
Type
Type
Type
Type
0x00
0x3
0x6
0
0x06
0xE7
0x00
Default
Default
Default
Default
Default
VBI3_SLICE_DIST
VBI3_BITINC_HIGH
RESERVED
VBI3_CRWIN
VBI3_FRAME_CODE_LOW
VBI3_FRAME_CODE_HIGH
VBI3_FRAME_CODE_MID
Name
Name
Name
Name
Name
Conexant
Specifies the time window during which edge detection
(positive and negative) is inhibited. This window is based on
the clock run-in frequency. Avoids spurious edges from being
detected.
VBI3_CRWIN = 4 x pixel_rate x clock_runin_half_period x wr;
Where wr = window ratio, portion of cycle to inhibit detection
Slice level sample distance. Controls how often samples are
taken for the adaptive slice level routine. Distance is defined in
terms of 1/8 or a bit period time, where the bit period is
defined by BITINC. The parameter describes the number of
points where samples are NOT taken. Therefore, to take one
sample every four points, put three in this field.
Most significant nibble of the value used to increment a 14-bit
counter that measures the bit sample rate. A bit is sampled
when the 14-bit counter rolls over. The bit sample rate defines
the rate at which the waveform is sampled during the payload.
For biphase endcoding modes, this sample rate should be set
to 6 times the effective bit rate.
VBI3_BITINC = 2
Least significant byte of start code bit pattern in transmission
order
Middle byte of start code bit pattern in transmission order
Most significant byte of start code bit pattern in transmission
order
14
/ ((4 x pixel_rate) / bit_sample_rate)
Description
Description
Description
Description
Description
CX25840/1/2/3 Data Sheet
Address 0x467
Address 0x46A
Address 0x466
Address 0x468
Address 0x469
102284B
8/3/05