CX25870/871
2.0 Internal Registers
Flicker-Free Video Encoder with Ultrascale Technology
2.4 Reading Registers
Table 2-5. Programming Detail For All Read/Write Registers (11 of 16)
Bit/Register
Names
Bit Location
Bit 3–C6
Bit/Register Definition
0 = Configures the encoder to send/receive an active low HSYNC* digital signal
HSYNCI
(DEFAULT)
1 = Configures the encoder to send/receive an active high HSYNC* digital signal.
HSYNOFFSET[9:8]
HSYNOFFSET[7:0]
Bits [7:6]–70 and A 2s-complement number. The values range from –512 pixels to +511 pixels. This
bits [7:0]–6E
register manipulates the falling edge position of the digital HSYNC* output from the
CX25870/871. The default value is 0 and denotes the standard position of the HSYNC*
leading edge. This register is only effective in master interface.
HSYNWIDTH[5:0]
Bits [5:0]–70
Controls the duration/width of the digital HSYNC output pulse. Value will be hexadecimal
and its units are in terms of pixels. A value of 0 is a disallowed condition. The acceptable
range is 0x02 pixels to 0x3F pixels (=63 decimal). The default value is 0x02. Never set to
0. This register is only effective in master interface.
HUE_ADJ[7:0]
Bits [7:0]–5C
Adjust the color subcarrier phase during the video active region. Increasing this value by
1 unit has the effect of increasing the phase by (360/256) = 1.406 degrees.
IN_MODE[3] and
IN_MODE[2:0]
Bit 3–32 and bits This bit is used in conjunction with IN_MODE[2:0] to configure the encoder to receive a
[2:0]–C6
desired input pixel format. Format of input pixels when IN_MODE[3] = 0 (MSb of this
4-bit sequence):
0000 = 24-bit RGB multiplexed
0001 = 16-bit RGB multiplexed
0010 = 15-bit RGB multiplexed
0011 = 24-bit RGB nonmultiplexed
0100 = 24-bit YCrCb multiplexed
0101 = 16-bit YCrCb multiplexed
0110 = Alternate 16-bit YCrCb multiplexed
0111 = 24-bit YCrCb nonmultiplexed
Format of input pixels when IN_MODE[3] = 1(MSb of this 4-bit sequence):
1000 = Alternate 24-bit RGB multiplexed
1001 = Reserved
1010 = Alternate 16-bit RGB nonmultiplexed
1011 = Alternate 24-bit RGB nonmultiplexed
1100 = Alternate 24-bit YCrCb multiplexed
1101 = Reserved
1110 = Alternate 16-bit YCrCb nonmultiplexed
1111 = Alternate 24-bit YCrCb nonmultiplexed
LUMADLY[1:0]
Bits [1:0]–D6
Used to program the luminance delay in pixels for the CVBS_DLY and Y_DLY output
modes.
00 = No delay (DEFAULT)
01 = 1 pixel
10 = 2 pixels
11 = 3 pixels
MCB[7:0]
Bits [7:0]–AA
Bits [7:0]–3E
Multiplication factor for Cb (or B-Y) component prior to subcarrier modulation.
MCOMPU[7:0]
Multiplication factor for component video U output.
Value 0x80 (DEFAULT) represents 1.0 scale factor.
MCOMPV[7:0]
MCOMPY[7:0]
MCR[7:0]
Bits [7:0]–40
Bits [7:0]–3C
Bits [7:0]–A8
Multiplication factor for component video V output.
Value 0x80 (DEFAULT) represents 1.0 scale factor.
Multiplication factor for component video Y output.
Value 0x80 (DEFAULT) represents 1.0. scale factor.
Multiplication factor for Cr (or R-Y) component prior to subcarrier modulation.
100381B
Conexant
2-19
CONEXANT [ CONEXANT SYSTEMS, INC ]
