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The RA8875 is a powerful TFT driver chip. It is a perfect match for any chip that wants to draw on a big TFT screen but doesn't quite have the oomph (whether it be hardware or speed). Inside is 768KB of RAM, so it can buffer the 4", 5" or 7" TFT Displays with up to 800x480 pixels (and depending on the screen size also have double overlaying). The interface is SPI with a very basic register read/write method of communication (no strange and convoluted packets).
The chip has a range of hardware-accelerated shapes such as lines, rectangles, triangles, ellipses, built in and round-rects. There is also a built in English/European font set (see the datasheet section 7-4-1 for the font table) This makes it possible to draw fast even over SPI. The RA8875 can also handle standard 4-wire resistive touchscreens over the same SPI interface to save you pins.
There's an IRQ pin that you can use to help manage touch interrupts. On the PCB we have the main chip, level shifting so you can use safely with 3-5V logic. There is also a 3V regulator to provide clean power to the chip and the display. For the backlight, there is a constant-current booster that can provide 25mA or 50mA at up to 24V. The connector to the screen is a classic '40 pin' connector.