cx25840 Conexant Systems, Inc., cx25840 Datasheet - Page 223

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

CX25840/1/2/3 Data Sheet
102284B
8/3/05
VBI Custom 2 Miscellaneous
[7]
[6:4]
[3:0]
VBI Custom 3 Horizontal Delay
[7:0]
VBI Custom 3 Bit Increment
[7:0]
Bits
Bits
Bits
RW
RW
RW
RW
RW
Type
Type
Type
0
011
0x4
0x6E
0xCA
Default
Default
Default
VBI2_HAM_EN
VBI2_FIFO_MODE
VBI2_FORMAT_TYPE
VBI3_HDELAY
VBI3_BITINC_LOW
Name
Name
Name
Conexant
Delay from internal hreset signal to start of clock run-in in
number pixel clock cycles.
VBI3_HDELAY = (hdelay(uS) x pixel_rate (MHz)) – 13
Enable hamming comparison for framing comparison when
this bit is set. When set VBI2_FRAME_CODE[3:0] are used for
hamming comparison.
Determines which payload FIFO is loaded.
000 = Do not load to payload FIFO
001 = Load to Gemstar 1x FIFO
010 = Load to CC FIFO
011 = Load to WSS FIFO
100 = Load to Gemstar 2x FIFO
Specifies basic VBI decoding model. Find the standard format
which most closely matches the intended format, and program
this field to match the type field encoding specified in the
VBI_LINE_CTRLx registers. Special operating modes are
enabled based on the format type as described below:
0000 = RESERVED
0101, 1010, 0011 = Teletext: Enable packet address filter
0011 = Enable Moji style byte alignment: First 6 bits go into
separate byte packet. 525-line modes only.
0100 = Wide-screen signaling: Assume signal includes single
sync pulse, and no frame code. 525-line mode only.
0100 = Wide-screen signaling: Implement WSS625 style
biphase decoding. 625-line mode only.
0101 = VITC: Assume sync pulses every 8 bits
0110, 0111, 1000 = Closed caption: Assume 50-IRE signal
amplitude
1001 = VPS: Implement VPS style biphase decoding
Least significant byte 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
14
/ ((4 x pixel_rate) / bit_sample_rate)
Description
Description
Description
Address 0x464
Address 0x463
Address 0x465
Register Map
5-81