
L64005 MPEG-2 Audio/Video Decoder Technical Manual
6-13
Final Rev F
Copyright 1996 by LSI Logic Corporation. All rights reserved.
6.5.1.1 Horizontal Timing
Horizontal timing parameters are measured in terms of the device clock,
and are accurate to within one clock pulse. The user must write to the
control registers over the L64005 user interface to set these parameters.
If the L64005 is in Master Mode, all horizontal timing parameters—equal-
ization, serration, and horizontal sync pulse—must be programmed.
Figure 6.8
Horizontal Sync
Timing
Please note for the above equation:
1.
Values of all parameters are stated in terms of device clocks (27-Mhz
clock cycles.)
2.
Program the value of parameter “Half Line Time” into Group 7, Reg-
ister 18. The actual value programmed into this register is (Half Line
Time - 1). Therefore, the value (Half Line Time + 1) is used to com-
pensate for the subtracted “1”.
3.
Program the value of parameter “Horizontal Blank Width” into Group
7, Register 16. The actual value programmed into this register is
(Horizontal Blank Width - 5). The value of “Active Image Done” is
also (Active Image Done - 5), therefore no modication to the equa-
tion is necessary.
4.
Program the value of parameter “Active Image Done” into Group 7,
Register 17. The actual value programmed into this register is (Active
Image Done - 5). Since the value of “Horizontal Blank Width” is also
(Horizontal Blank Width - 5), no modication to the equation is nec-
essary.
Active Image Width
Active Image Done
Horizontal Blank Width
H BLANK
HS
HSYNC Width
Half Line Time
Full Line Time
1. (Half Line Time + 1) - Horizontal Blank Width + Active Image Done =Active Image
Width.
MD95.221