Motorola MPC823e Reference Manual page 1011

LCD Controller
18.3.7 Timing Control
The LCD controller is clocked by the LCDCLK signal that the system interface unit generates
by dividing the system clock. The LCDCLK signal is used to convert frame data to pixel
format. The division factor depends on the type of display you are using. Use the following
table to program LCDCLK. For information on the system clock and reset control register,
refer to Section 5 Clocks and Power Control .
BITS PER PIXEL/PANEL TYPE
1-Bit Black/White
2-Bit Grayscale
4-Bit Grayscale
4- or 8-Bit Color Passive
4- or 8-Bit Color Active (TFT)
NOTE: F denotes the LCD panel clock frequency.
18.3.8 Contrast and Brightness Control
If you do not use frame rate control to handle contrast and brightness, then you will need
external circuitry to give you more control for those panel inputs. Refer to your panel
specifications to find out what you need for your panel.
18.3.9 The LCD Interface
The LCD interface provides drivers for the data, clock, and control signals to the LCD
display. It consists of 12 data bits (LD[0:8], LCD_A, LCD_B, and LCD_C), a data clock
(SHIFT/CLK), vertical and horizontal control (FRAME/VSYNC and LOAD/HSYNC), and
panel control (LCD_AC/LOE). You can program the polarity of each of these signals. The
LCD interface can be configured to support a variety of panels—single-scan, dual-scan,
color, monochrome, passive, and active.
18-14
Table 18-1. LCDCLK Programming
LCD PANEL TYPE/DATA WIDTH
SINGLE-SCAN
12-BIT 8-BIT
—
— 2 * F
— 2 * F
— 3 * F
F
MPC823e REFERENCE MANUAL
DUAL-SCAN
4-BIT 8-BIT
F F F
F 2 * F
F 2 * F
2 * F 2 * F
— — —
4-BIT
F
F
F
—
—
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