2.0 Internal Registers
CX25870/871
2.4 Reading Registers
Flicker-Free Video Encoder with Ultrascale Technology
Table 2-5. Programming Detail For All Read/Write Registers (2 of 16)
Bit/Register
Bit Location
Names
Bit/Register Definition
Chroma Attenuation. Used for saturation control.
CATTENUATE[2:0]
Bits [2:0]–CC
000 = 1.0 gain No Attenuation (DEFAULT)
001 = 15/16 gain
010 = 7/8 gain
011 = 3/4 gain
100 = 1/2 gain
101 = 1/4 gain
110 = 1/8 gain
111 = 0 gain (Force Chroma to 0)
CC_ADD[11:0]
CCF1B1[7:0]
CCF1B2[7:0]
CCF2B1[7:0]
CCF2B2[7:0]
CCORING[2:0]
Bits [3:0]–D4 and Closed-captioning DTO increment.
bits [7:0]–D2
Bits [7:0]–C0
Bits [7:0]–C2
Bits [7:0]–BC
Bits [7:0]–BE
Bits [5:3]–CC
This is the first byte of closed-caption information for the odd field, line 21 for NTSC or
line 22 for PAL. Data is encoded LSB first.
This is the second byte of closed-caption information for the odd field, line 21 for NTSC
or line 22 for PAL. Data is encoded LSB first.
This is the first byte of closed-caption information for the even field, line 284 for NTSC or
line 335 for PAL. Data is encoded LSB first.
This is the second byte of closed-caption information for the even field, line 284 for
NTSC or line 335 for PAL. Data is encoded LSB first.
Chroma Coring. Values below the CCORING[2:0] limit are automatically clamped to a
saturation value of 0.
000 = Bypass (DEFAULT)
001 = 1/128 of range ( 1/256 of range)
010 = 1/64 of range ( 1/128 of range)
011 = 1/32 of range ( 1/64 of range)
100 = 1/16 of range ( 1/32 of range)
101 = 1/8 of range ( 1/16 of range)
110 = 1/4 of range ( 1/8 of range)
111 = Reserved
CCR_START[9]
CCR_START[8]
CCR_START[7:0]
Bit 7 of D6, bit 4
of D4, and bits
[7:0] of D0
Closed-captioning clock run-in start in clock cycles from leading edge of HSYNC*.
CCSEL[3:0]
Bits [3:0]–5E
Line position of Closed Captioning (CC) Content.
Controls which line Closed Captioning (CC) data is encoded. Each line enable is
independent.
0001 = Closed Captioning (CC) on line 19 (525-line) and line 21 (625-line)
0010 = Closed Captioning (CC) on line 20 (525-line) and line 22 (625-line)
0100 = Closed Captioning (CC) on line 21 (525-line) and line 23 (625-line) (DEFAULT)
1000 = Closed Captioning (CC) on line 22 (525-line) and line 24 (625-line)
CHECK_STAT
CHROMA_BW
Bit 6–BA
Bit7–D8
Writing a 1 to this bit checks the status of the monitor connections at the DAC output.
This is also automatically performed on any reset condition, including a software reset.
This bit must be cleared by the serial interface master.
0 = Normal chroma bandwidth. See Figure 1-28 (DEFAULT).
1 = Wide chroma bandwidth. See Figure 1-29.
2-10
Conexant
100381B
CONEXANT [ CONEXANT SYSTEMS, INC ]
