User`s guide

Intel
®
StrongARM
®
SA-1110 Microprocessor Development Board User’s Guide 4-17
Hardware Considerations
mappings between the SA-1110 and the LCD that the CPLD can be programmed to accommodate.
In addition, no two LCDs are the same and the CPLD allows developers to adapt designs to support
other displays types or NTSC/PAL TV encoders. This LCD CPLD facilitates the adaptation of
many different LCD types to the SA-1110 Development Board.
The SA-1110 Development Board provides all required support circuitry for the 3.9” LCD and a
matching Hirose 50-pin connector for direct interfacing to this panel.
To use an LCD other than the Sharp 3.9”, a custom adapter flex print cable (FPC) must be
designed.
4.6.2.2 Memory Pixel Representations Versus Physical Pixel Interface
A frequent source of confusion with SA-1100 and SA-1110 LCD applications is the number of bits
per pixel. It is important to distinguish between the bits per pixel representation in SA-1110 system
memory and the bits per pixel of the physical interface between the SA-1110 and the LCD panel.
An operating system may use eight bit pixels in system memory while the SA-1110 LCD controller
color look up table (also known as a color palette) maps the eight bit memory pixels to twelve bit
physical pixels (RGB444) that appear on the LCD pixel data pins.
4.6.2.3 Mapping 18 Bit LCDs to 16 Bits of Pixel Data
Most TFT color LCDs have 18 bit interfaces which expect six bits of red, six bits of green and six
bits of blue, written as RGB 666. The SA-1110 Development Board provides 16 bits per pixel
maximum. To map the 16 bit SA-1110 LCD interface to an 18-bit color TFT LCD the LSBs of the
red and blue colors must be connected to ground. This results in five bits of blue, six bits of green
and five bits of red (RGB 565). The perceived color difference between RGB 666 and RGB 565 is
minimal.
4.6.2.4 LCD Backlight Frontlight Support
The SA-1110 Development Board provides a connector suitable for powering a backlight inverter
circuit. The raw battery voltage is available on the backlight connector to power a backlight
inverter. A program controlled GPIO pin allows switching the backlight/frontlight on and off. A
PWM DAC signal from the SA-1111 Development Module is also available on the connector to
control brightness if required by the display system.
Note: The design does not include a backlight power supply.
4.7 Debugging
This section describes the SA-1110 Development Board’s keypad, debug and functional switches.
4.7.1 Keypad
A 5 x 4 matrix keypad suitable for use with telephone applications
1
is supported in the SA-1111
Development Module. The primary use of the keypad is as a simple input device for system
debugging and diagnostic interaction. Applications may also use this resource.
1. The SA-1110 Development Platform has not been certified as compliant with FCC, CE, UC, or PTT telephone standards or regulations.