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Figure 4-6 The tPad Starter Pattern sub item
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This demonstration shows a simple picture viewer implementation using Nios II based SOPC
system. It reads JPEG images stored on SD Card and displays them on the LCD. The Nios II CPU
decodes the images and fills the raw result data into frame buffers in SDRAM. The tPad will show
the image the buffer being displayed points to. When users touch the LCD Touch Panel, it will
proceed to display the next buffered image until there is no filled buffer and enter the
Loading
phase.
Figure 4-7
shows the block diagram of this demonstration.
The Nios II CPU here takes a key roll in the demonstration. It is responsible of decoding the JPEG
images and coordinates the works of all the peripherals. The touch panel handling program uses the
timer as a regular interrupter and periodically updates the pen state and sampled coordinates.
