saa6703ah NXP Semiconductors, saa6703ah Datasheet - Page 55

• Manufacturer Part Number: saa6703ah
• Description: Xga Analog Input Flat Panel Controller.
• Manufacturer: NXP Semiconductors

Philips Semiconductors
7.10.3.4
To help adjusting the phase for the ADCs, the SAA6703AH
has a built-in phase distortion measurement which is
calculating a 30-bit indicator value of a defined area of the
video signal (see Table 35). The area for phase distortion
measurements may contain active video or blanking. The
area is defined by applying the upper left and lower right
corner of the area to ref_col_0, ref_row_0 and ref_col_1,
ref_row_1 respectively. Assuming a stable input picture
with different pixel values inside the measurement
window, the phase adjustment can be done by shifting the
ADC phases and reading out the phase distortion indicator
value of bits eval_row_0 and eval_col_0 for the maximum
distortion value and eval_row_1 and eval_col_1 for the
minimum distortion value. The best sampling phase
corresponds to the highest value of the phase distortion
indicator.
Table 35 Mode 11 (phase distortion measurement)
2004 Apr 01
Input values
aa_submode[1:0]
aa_cycles[1:0]
ref_col_0[10:0]
ref_row_0[11:0]
ref_col_1[10:0]
ref_row_1[11:0]
Output values
eval_col_0[15:0]
eval_row_0[15:0]
eval_col_1[15:0]
eval_row_1[15:0]
ref_pixel_blue_0[5:0]
ref_pixel_red_1[7:0]
ref_pixel_green_1[7:0] signature[15:8]
ref_pixel_blue_1[7:0]
XGA analog input flat panel controller
BIT
Phase distortion measurement
not used
measurement interval
measurement area upper left corner column
measurement area upper left corner row
measurement area lower right corner column
measurement area lower right corner row
maximum of distortion[15:0]
maximum of distortion[29:16]
minimum of distortion[15:0]
minimum of distortion[29:16]
signature[29:24]
signature[23:16]
signature[7:0]
00: 1 frame
01: 4 frames
10: 8 frames
11: 16 frames
55
This phase distortion value could also be used for the
frequency adjustment by sweeping the input frequency
around the assumed target frequency.
When auto-adjustment is in phase distortion mode, a
signature is calculated for each frame. Changes inside the
input stream can be detected by reading the signature bits
ref_pixel_blue_0, ref_pixel_red_1, ref_pixel_green_1 and
ref_pixel_blue_1. For still pictures, the signature does not
change.
DESCRIPTION
SAA6703AH
Product specification