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3-2 PXA250 and PXA210 Applications Processor Design Guide
LCD Display Controller
For passive displays, the pins described in Table 3-2 are required connections between the PXA250
applications processor and your LCD panel.
3.2.1 Typical Connections for Passive Panel Displays
The following diagrams are typical connections and serve a guide for designing systems which
contain passive LCD displays. Panels differ on which is the panel’s lest significant bit (Refer to the
LCD panel reference documentation for the lest significant bit.) Each figure indicates the top-left
pixel (1,1) bit. While dual panels indicates the top-left pixel (1,n/2) of the upper and lower panels
and color passive panels show the top-left-pixel color bits.
3.2.1.1 Passive Monochrome Single Panel Displays
Figure 3-1 is a typical single-panel-monochrome passive display connection.
Color Dual N/A
Top L_DD<7:0>
Bottom L_DD<15:8>
NOTE: 1. Double pixel data mode (DPD)=1.
Table 3-1. LCD Controller Data Pin Utilization (Sheet 2 of 2)
Color/
Monochrome
Panel
Single/
Dual Panel
Double-Pixel
Mode
Screen Portion Pins
Table 3-2. Passive Display Pins Required
PXA250 Pin LCD Panel Pin PIn Type
1
Definition
L_DD DU_x, DL_x Output
Data lines used to transmit either four or eight data values at a time to
the LCD display. For monochrome displays, each pin value represents
a single pixel; for passive color, groupings of three pin values represent
one pixel (red, green, and blue data values). Either the bottom four pins
(L_DD<3:0>), the bottom 8 pins (L_DD<7:0>) or all 16 pixel data pins
(L_DD<15:0>)will be used as shown in Table 3-1
L_PCLK Pixel_Clock Output
Pixel Clock - used by the LCD display to clock the pixel data into the
line shift register.
L_LCLK Line_Clock Output
Line Clock - used by the LCD display to signal the end of a line of pixels
that transfers the line data from the shift register to the screen and
increment the line pointers.
L_FCLK Frame_Clock Output
Frame Clock - used by the LCD displays to signal the start of a new
frame of pixels that resets the line pointers to the top of the screen.
L_BIAS Bias Output
AC bias used to signal the LCD display to switch the polarity of the
power supplies to the row and column axis of the screen to counteract
DC offset.
N/A Vcon
2
N/A
Contrast Voltage - Adjustable voltage input to LCD panel - external
voltage circuitry is required (no pin available on PXA250).
NOTES:
1. “Pin Type” is in reference to the PXA250 applications processor. Therefore, outputs are pins that drive a signal from the processor to another
device.
2. Vcon is a signal external to the PXA250 applications processor. Please refer to “Contrast Voltage” on page 8