Texas Instruments DM38x DaVinci, User Manual

Page: 118 / 956

( ) ( )
( ) ( )
sin 2 cos 2
sin 2 cos 2
sc sc
sc sc
U f V f NTSC
C
U f V f PAL
π π
π π

+

= 
±

K
K
1 1
0 27
1024 2
sc
SCP
f SCP MHz
SCP
 
= × + ×
 
 
Internal Modules
www.ti.com
118 SPRUHI7A – December 2012 – Revised June 2016
Submit Documentation Feedback
Copyright © 2012–2016, Texas Instruments Incorporated
High-Definition Video Processing Subsystem (HDVPSS)
1.2.6.2.7.2.4 QAM Modulation
The VENC generates the sub-carrier by internal direct digital synthesizer (DDS). The frequency of sub-
carrier is determined by three increment parameters, SCP0, SCP1 and SCP2 as follows:
Typical settings of these parameters are shown in Table 1-40 .
Table 1-40. Sub-carrier Increment Parameters
TV Format SCP0 SCP1 SCP2 Frequency
NTSC-M/J 135 25 33 3.579545454… MHz
NTSC-4.43 168 2516 16875 4.433618749… MHz
PAL-B/D/G/H/K/I 168 2516 16875 4.433618749… MHz
PAL-M 135 87 143 3.575611888… MHz
PAL-N 168 2516 16875 4.433618749… MHz
PAL-Nc 135 14391 16875 3.58205625 MHz
PAL-60 168 2516 16875 4.433618749… MHz
The sub-carrier to horizontal (SC-H) phase can be controlled by the user. Writing the SCSD register
automatically initializes the sub-carrier phase as the value specified in SCSD. The initialization is occurred
at the line 4 in the color field 1 for NTSC and the line 1 in the color field 1 for PAL. The phase resolution of
DDS is (1/1024)*360°.
Chroma modulation is performed as expressed by: