Modes Of Operation Overview; Passive Monochrome Single-Scan Mode; Signals; Passive Display Pins Required - Intel PXA27 Series Design Manual

LCD Interface
7.5

Modes of Operation Overview

7.5.1

Passive Monochrome Single-Scan Mode

Passive monochrome single-scan displays are the simplest displays to set up. A maximum gray-
scale range of 256 shades (8 bits) is supported.
7.5.1.1

Signals

For passive monochrome single-scan displays, the pins described in
connections between the PXA27x processor and LCD panel.
Table 7-3. Passive Display Pins Required
PXA27x
LCD Panel Pin
processor Pin
LDD<3:0> D<3:0>
L_PCLK_WR Pixel_Clock
L_LCLK_A0 Line_Clock
L_FCLK_RD Frame_Clock
L_BIAS Bias
2
N/A Vcon
NOTES:
1. "Pin Type" is in reference to the PXA27x processor. Therefore, outputs are pins that drive a signal from the processor to
another device.
2. Vcon is a signal external to the PXA27x processor. Refer to
Note: Names used for "LCD Panel Pin" are representative names and do not match those on all LCD
panels. Similarly, not all signals are required for all modes of operation. Refer to the LCD panel
reference documentation for information on:
•
Specific signals required for correct LCD operation
•
Correct names of the signals used by the LCD panel manufacturer
II:7-6
1
PIn Type Definition
Data lines used to transmit four data values at a time to the LCD
Output
display. Each pin value represents a single pixel.
Pixel Clock – used by the LCD display to clock the pixel data into the
Output
line shift register.
Line Clock – used by the LCD display to signal the end of a line of
Output pixels that transfers the line data from the shift register to the screen
and increment the line pointers.
Frame Clock – used by the LCD displays to signal the start of a new
Output
frame of pixels that resets the line pointers to the top of the screen.
AC bias used to signal the LCD display to switch the polarity of the
Output power supplies to the row and column axis of the screen to counteract
DC offset.
Contrast voltage – adjustable voltage input to LCD panel – external
N/A
voltage circuitry is required (no pin available on PXA27x processor).
Section 7.4.1, "Contrast Voltage,"
Intel
Table 7-3
for detailed information.
®
PXA27x Processor Family Design Guide
are required for