How do you maintain power to the DragonBall chip when power is removed?
A SuperCap is used to maintain power to the whole DragonBall chip when main power is removed. PLLVCC is derived from VCC for PLL power supply only. RTC uses VCC power supply, so to maintain RTC data, both VCC and PLVCC must be kept at a valid voltage level. If you put your system to sleep mode before removing other main power, DragonBall consumes less than 20 uA at 3.3V. 4. How do I use the LCDCONTRAST pin? It looks like I can use it to drive the contrast on my LCD, but what other logic do I need, since the pin won’t handle the current required by the LCD’s contrast pin? Answer: LCDCONTRAST is used to drive different duty cycle clocks to control (on/off) bias voltage to LCD panel. Using a FET switch and a cap will do it. Version 2.0 EZ spec has detailed info on LCDPWM function, which generates the LCDCONTRAST signal. 5. I’m having problems getting the EZ ADS board to work with the Diab 4.1A compiler and SDS 7.2 debugger. The board will load the example .out files from the SDS tutorial
