Cirrus Logic CS4955 - Manual (Page 21)

CS4954 CS4955
DS278F6 21
5.4 Digital Video Input Modes
The CS4954/5 provides two different digital video
input modes that are selectable through the
IN_MODE bit in the CONTROL_0 Register.
In Mode 0 and upon RESET, the CS4954/5 de-
faults to output a solid color (one of a possible of
256 colors). The background color is selected by
writing the BKG_COLOR Register (0x08). The
colorspace of the register is RGB 3:3:2 and is unaf-
fected by gamma correction. The default color fol-
lowing RESET is blue.
In Mode 1 the CS4954/5 supports a single 8-bit
27 MHz CbYCrY source as input on the V [7:0]
pins. Input video timing can be ITU-R.BT601 mas-
ter or slave or ITU-R.BT656.
5.5 Multi-standard Output Format Modes
The CS4954/5 supports a wide range of output for-
mats compatible with worldwide broadcast stan-
dards. These formats include NTSC-M, NTSC-J,
PAL-B/D/G/H/I, PAL-M, PAL-N, and PAL Com-
bination N (PAL-Nc) which is the broadcast stan-
dard used in Argentina. After RESET, the CS4954/5
defaults to NTSC-M operation with ITU-R.BT601
analog timing. NTSC-J can also be supported in the
Japanese format by turning off the 7.5 IRE pedestal
through the PED bit in the CONTROL_1 Register
(0x01).
Output formats are configured by writing control
registers with the values shown in Table
3 .
261 262 1 2 3 4 5 6 7 8 9
Start of
VSYNC
10 22
Field 1
Burst begins with positive half-cycle Burst begins with negative half-cycle
Burst phase = reference phase = 180 relative to B-Y 0 Burst phase = reference phase = 180 relative to B-Y 0
262 263 1 2 3 4 5 6 7 8 9 10 22
261 262 1 2 3 4 5 6 7 8 9 10 22
262 263 1 2 3 4 5 6 7 8 9 10 22
Field 2
Field 3
Field 4
Start of
VSYNC
Figure 9. NTSC Video Non-Interlaced Progressive Scan Timing
NOTE 1: The FIELD pin (pin 9) remains an output pin in SLAVE mode. However, the FIELD pin state does not
toggle in SLAVE mode and its output state should be considered random.