5.2 Memory LCD-TFT Display
A 1.28-inch SHARP Memory LCD-TFT is available on the kit to enable interactive applications to be developed. The display has a high
resolution of 128 by 128 pixels, and consumes very little power. It is a reflective monochrome display, so each pixel can only be light or
dark, and no backlight is needed in normal daylight conditions. Data sent to the display is stored in the pixels on the glass, which means
no continous refreshing is required to maintain a static image.
The display interface consists of an SPI-compatible serial interface and some extra control signals. Pixels are not individually addressa-
ble, instead data is sent to the display one line (128 bits) at a time.
The Memory LCD-TFT display is shared with the kit's board controller, allowing the board controller application to display useful infor-
mation when the user application is not using the display. The user application always controls ownership of the display with the
DISP_ENABLE signal:
• DISP_ENABLE = LOW: The board controller has control of the display
• DISP_ENABLE = HIGH: The user application (BGM13P) has control of the display
Power to the display is sourced from the target application power domain when the BGM13P controls the display, and from the board
controller's power domain when the DISP_ENABLE line is low. Data is clocked in on DISP_SI when DISP_CS is high, and the clock is
sent on DISP_SCLK. The maximum supported clock speed is 1.1 MHz.
DISP_EXTCOMIN is the "COM Inversion" line. It must be pulsed periodically to prevent static build-up in the display itself. Refer to the
display application information for details on driving the display:
http://www.sharpmemorylcd.com/1-28-inch-memory-lcd.html
PC8 (US1_CLK #11)
PC6 (US1_TX #11)
PD14 (US1_CS #19)
PD13 (GPIO)
PD15 (GPIO)
BGM13P
0: Board Controller controls display
1: BGM13P controls display
Figure 5.2. 128x128 Pixel Memory LCD
UG338: BGM13P22 Blue Gecko Module Radio Board User's Guide
Peripherals
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