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thd
thf
thp
(2)
thb
(2)
Vertical signal
tv
tvd
tvf
tvp
(2)
tvb
(2)
Remarks:
(1) Unit: CLK=1/f
scanning a line;
(2) It is necessary to keep tvp+tvb=12 and thp+thb=43 in sync mode. DE mode is
unnecessary to keep it.
From the figure above, we can learn that:
The total time for scanning a line is: th = thp + thb + thd + thf; in the period of thd, when a
clock plus comes, a pixel data will be transmitted via the parallel data interface. And there
are 480 pixels each line for this LCD, so thd=480;
The duration for scanning a frame is: tv = tvp + tvb + tvd + tvf；Hsync can be regarded as
the clock of vertical signals. A clock cycle of Hsync refers to the duration for LCD
displaying a line. When a falling edge comes in Hsync, a new line will be displayed in the
LCD. However, the actual data transmission only occurs in the period of tvd. And the LCD
will display the new line in this case. There are 272 lines for this LCD, so tvd = 272.
Other parameters can be modified as required, according to the specifications listed in the
tables above.
2. Hardware description
Pin No.
Symbol
1
5V
2
3
B0
4
B1
5
B2
4.3inch 480x272 Touch LCD (A) User Manual
Horizontal
display
period
Horizontal
front
porch
Horizontal
pulse
width
Horizontal
back
porch
Vertical
cycle
Vertical
display
period
Vertical
front porch
Vertical
pulse width
Vertical
back porch
, it is the duration for scanning a pixel; H=th, it is the duration for
CLK
Descriptions
5V power
supply
Data line
480
480
480
2
2
82
2
41
41
2
2
41
285
286
399
272
272
272
1
2
227
1
10
11
1
2
11
I/O
Functions
I
Supply 5V power voltage
I
Blue pallet data line
CLK
(1)
CLK
(1)
CLK
(1)
CLK
(1)
H
(1)
H
(1)
H
(1)
H
(1)
H
(1)
3
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