cx25870 Conexant Systems, Inc., cx25870 Datasheet - Page 44

• Manufacturer Part Number: cx25870
• Description: Video Encoder With Adaptive Flicker Filtering And Hdtv Output
• Manufacturer: Conexant Systems, Inc.

1.0 Functional Description
1.3 Device Description
1.3.11 Input Pixel Timing
1.3.12 YCrCb Inputs (For Standard TV Outputs)
1-28
The device can accept the input data in either RGB or YCrCb color spaces. Data
can be input either a full pixel at a time clocked in on the rising edge of CLKI
only, or in various multiplexed modes, using both edges of CLKI.
RGB format, either 15-bit 5:5:5, 16 bit 5:6:5, or 24-bit RGB can be input. In
16-bit 4:2:2 YCrCb input format, multiplexed Y, Cr, and Cb data is input through
the P[11:4] or P[7:0]input pins. The Y data is input on the falling edge of CLKI.
The Cr/Cb data is input on the rising edge of CLKI. The Cb/Y/Cr/Y sequence
begins at the first active pixel. An additional 4:2:2 YCrCb input format maps Y to
P[19:12] and Cr/Cb multiplexed on P[11:4]. In 24-bit 4:4:4 YCrCb input format,
multiplexed Y, Cr, and Cb data is input through the P[11:0] inputs. Both the rising
and falling edge of CLKI sample the input data.
format or 8 bits at a time in 15/16 bit RGB format on both the rising and falling
edge of CLKI.
multiplexed input formats.
format can utilize the nonmultiplexed clocking method. See
pin-to-bit assignments.
Y has a nominal range of 16–235; Cr and Cb have a nominal range of 16–240,
with 128 (80 hex) equal to zero. Values of 0 and 255 are interpreted as 1 and 254,
respectively. Y values of 1–15 and 236–254, and CrCb values of 1–15 and
241–254, are interpreted as valid linear values.
In YCrCb format, either 24-bit 4:4:4 data or 16-bit 4:2:2 data can be input. In
In RGB input format, input data is sampled as 12 bits at a time in 24-bit RGB
In addition, all 24-bit formats, a 16-bit RGB format, and a 16-bit YCrCb
Table 1-2
Conexant
shows the data pin assignments for all available
Flicker-Free Video Encoder with Ultrascale Technology
Table 1-3
CX25870/871
for these
100381B