Focus Enhancements FS454 Data Sheet

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FS453/4 AND FS455/6 
 
DATA SHEET: HARDWARE REFERENCE 
9.4.3.1 Pseudo-master Mode 
In Pseudo-master Mode shown below, the FS453 has complete control of the graphics system clock, but 
relinquishes the video sync signals to the GCC.  The GCC provides the FS453 with a complete 
complement of digital video signals at the rate of the FS453 clock (CLKOUT).   
 
 
 
 
Figure 13: Pixel Clock Pseudo-master Mode 
PSEUDO-MASTER MODE DIAGRAM 
27 
 
GCC
 
 
FS453 
CLK OUT 
CLK IN 
SYNC
DATA 
9.4.3.2 Slave Mode 
In Slave Mode shown below, the FS453 is under the complete control of the GCC.  The GCC provides 
the FS453 with all of the signals needed to produce an analog video signal.  One must be careful when 
using the Slave Mode.  Since the FS453 cannot control the GCC clock, the scalability of video images is 
limited.  Additionally, if the GCC has a poor quality clock, the system will produce poor quality images. 
 
 
 
 
Figure 14: Pixel Clock Slave Mode 
 
GCC
 
 
FS453 
27 MHz 
DATA
SYNC
CLK IN 
SLAVE MODE DIAGRAM
JANUARY, 2005, VERSION 3.0 
36 
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©2003-4 FOCUS ENHANCEMENTS, INC. 
FOCUS Enhancements Semiconductor