CX25870/871
2.0 Internal Registers
Flicker-Free Video Encoder with Ultrascale Technology
2.4 Reading Registers
Table 2-5 contains the data details for the CX25870/871 read/write registers.
Table 2-5. Programming Detail For All Read/Write Registers (1 of 16)
Bit/Register
Names
Bit Location
Bit 4–3A
Bit/Register Definition
0 = 13.500 crystal operation. (DEFAULT)
14318_XTAL
1 = 14.318 MHz crystal operation. Adjusts autoconfiguration register values for the
alternative crystal frequency.
625LINE
Bit 2–A2
The default state of this bit will be 1 if the PAL pin is 1.
0 = 525-line format (NTSC-M, NTSC-J, PAL-M).
1 = 625-line format (PAL-BDGHI, PAL-N, PAL-Nc, SECAM).
ADPT_FF
Bit 7–34
Bit 7–32
0 = Disable adaptive flicker filter. (DEFAULT)
1 = Enable adaptive flicker filter.
AUTO_CHK
0 = Normal operation. (DEFAULT)
1 = The status of the monitor connections will be automatically checked once per frame
during the VBI (vertical blanking interval).
BLANKI
Bit 5–D6
Bit 4–6C
0 = Active low BLANK* pin. (DEFAULT)
1 = Active high BLANK* pin.
BLNK_IGNORE
0 = Use BLANK* pin to indicate the active pixel region in CCIR 656 mode. (DEFAULT)
1 = Use registers H_BLANKI & V_BLANKI to determine the active pixel region in CCIR
656 mode.
BPB_SYNC_DIS
Bit 3–2E
This bit is only effective when OUT_MODE[1:0] = 11, HDTV_EN = 1, and RASTER_SEL is
nonzero.
0 = Enables trilevel sync on HDTV Blue or PB output. (DEFAULT)
1 = Disables trilevel sync on HDTV Blue or PB output. This bit will have to be set
manually for EIA-770.3 compliance.
BST_AMP[7:0]
BY_PLL
Bits[7:0]–A6
Bit 6–A0
Color burst amplitude factor. Each bit adjustment represents 1.25 mV of burst
amplitude.
0 = Use on chip PLL (DEFAULT)
1 = Bypass PLL (encoder clock is crystal frequency).
BY_YCCR
Bit 6–D8
0 = Normal operation (DEFAULT)
1 = Bypass luma cross color reduction filter. Optimal standard definition quality most
often realized with this setting.
C_ALTFF[1:0]
Bits [4:3]–34
Bits [5:3]–36
Chroma alternate flicker filter selection. This bit will only have an effect when ADPT_FF is
set. C_ALTFF should always be programmed to a value greater than or equal to F_SELC.
00 = 5 line (DEFAULT)
01 = 2 line
10 = 3 line
11 = 4 line
C_THRESH[2:0]
Controls the sensitivity or limit of turning on the alternate flicker filter for chroma in
adaptive mode. (DEFAULT = 000)
100381B
Conexant
2-9
CONEXANT [ CONEXANT SYSTEMS, INC ]
