LCD Display Controller

Figure 3-5. Passive Color Dual Panel Displays Typical Connection

PXA250 Processor

L_DD0

DU_0

L_DD1

DU_1

L_DD2

DU_2

L_DD3

DU_3

L_DD4

DU_4

L_DD5 - Top left Blue for upper panel

DU_5

L_DD6 - Top left Green for upper panel

DU_6

L_DD7 - Top left Red for upper panel

DU_7

L_PCLK

Pixel_Clock

L_LCLK

Line_Clock

L_FCLK

Frame_Clock

L_BIAS

Bias

L_DD8

DL_0

L_DD9

DL_1

L_DD10

DL_2

L_DD11

DL_3

L_DD12

DL_4

L_DD13 - Top left Blue for lower panel

DL_5

L_DD14 - Top left Green for lower panel

DL_6

L_DD15 - Top left Red for lower panel

DL_7

 

 

 

 

Upper Panel

LCD Display

Lower Panel

3.3Active (TFT) Displays

Because data is sent to the panel as raw 16-bit pixel data, active displays require16 data pins in order to transfer the pixel data from the controller. All 16 data lines are also required to drive one pixel value. The 16 bits of data describe the intensity level of the red, green and blue for each pixel. Typically, this is formatted as 5 bits for red, 6 bits for green and 5 bits for blue, but this can vary by display and is controlled by the software writing to the frame buffer. Refer to the display datasheet to ensure that the correct the PXA250 applications processor LCD data lines are connected to the correct LCD panel data lines.

Many active displays actually have more than 16 data lines - usually 18 (6 of each color). For these panels it is recommended that the most significant lines of the panel lines are connected to the data lines from the PXA250 applications processor. This maintains the panel’s full range of colors but increases the granularity of the color spectrum with an insufficient number of data lines. All unused panel data lines can be tied either high or low. Other options include tying the LSB of red and blue to the next bit, R1 or B1.

For active displays, connect the pins described in Table 3-3between the PXA250 applications processor and the LCD panel.

PXA250 and PXA210 Applications Processor Design Guide

3-5

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Intel PXA250 and PXA210 manual Active TFT Displays, Passive Color Dual Panel Displays Typical Connection

PXA250 and PXA210 specifications

The Intel PXA250 and PXA210 processors, part of the Intel XScale architecture, were introduced in the early 2000s, targeting mobile and embedded applications. They are known for their low power consumption, high performance, and advanced multimedia capabilities, making them suitable for a wide range of devices, including PDAs, smartphones, and other portable computing devices.

The PXA250, which operates at clock speeds ranging from 400 MHz to 624 MHz, features a superscalar architecture that allows it to issue multiple instructions per clock cycle. This enhances the overall performance for demanding applications while maintaining low power usage. It supports a variety of peripheral interfaces, including USB, Ethernet, and various memory types, which contributes to its versatility in different product designs.

One of the key technologies in the PXA250 is the integrated Intel Smart Repeat Technology, which optimizes data processing, thereby reducing the amount of power consumed during operation. This feature is particularly important for battery-powered devices, as it extends the overall battery life, allowing for longer usage times in mobile environments. Additionally, the PXA250 includes a dedicated graphics acceleration unit, which enables enhanced graphics and multimedia performance suited to modern applications at the time.

In contrast, the PXA210 is a more entry-level processor, aimed at cost-sensitive applications. Operating at lower clock speeds, typically around 200 MHz to 400 MHz, it forgoes some of the advanced performance features of the PXA250 while still offering a good balance of performance and power efficiency. The PXA210 is less complex, making it suitable for simpler devices that do not require the extensive capabilities of the PXA250.

Both processors utilize the Intel XScale architecture, which is based on the ARM instruction set. They are built on a 0.13-micron process technology, enabling higher density and lower power consumption compared to their predecessors. With integrated memory controllers and bus interfaces, they facilitate efficient data handling and connectivity options.

In summary, both the Intel PXA250 and PXA210 processors played a crucial role in the evolution of mobile computing by providing powerful processing capabilities with energy efficiency. Their features and technologies enabled device manufacturers to create innovative products that catered to the growing demand for portable devices during that era.