Fujitsu MB91319 Series Hardware Manual page 582

CHAPTER 18 OSDC
■ Horizontal Display Period Control
Horizontal display period control is used to generate horizontal display periods for controlling the
output of display signals. In a horizontal display period, signals for display in horizontal directions
are output. Horizontal display periods can be set by commands. The following two types of
operation are done according to the setting of the HSYNC edge selection bit (HE bit) of the I/O
pin control command (command 13-0):
• Operation with the trailing edge selected for horizontal synchronization (HE bit = 0)
• Operation with the leading edge selected for horizontal synchronization (HE bit = 1)
Figure 18.3-11 shows an example of horizontal display period control.
- Operation with the trailing edge selected for horizontal synchronization (HE bit = 0)
HSYNC input
(HSYNC pin)
Horizontal
display period
- Operation with the leading edge selected for horizontal synchronization (HE bit = 1)
HSYNC input
(HSYNC pin)
Horizontal
display period
The start and end of a horizontal display period can be specified as follows:
❍ Horizontal display start timing
Display period control 3 (command 14-2): bits DXS10 to DXS0 = number of dot clock signals = 0
to 2047, set in units of 1 dot clock signals
❍ Horizontal display end timing
Display period control 4 (command 14-3): bits DXE10 to DXE0 = number of dot clock signals = 0
to 2047, set in units of 1 dot clock signals
Note:
When the following setting is performed, the display end timing setting is invalid. The display output
enabled period is set until the synchronization signal inputs.
DXS [10:0] (horizontal display start timing)
560
Figure 18.3-11 Horizontal Display Period Control
Display signal
Display signal output enabled
output disabled
Display start timing
Display signal
Display signal output enabled
output disabled
Display start timing
Display end timing
Display end timing
≥
DXE [1:0] (horizontal display end timing)
Display signal
output disabled
Display signal
output disabled