Raspberry Pi Display
- 32KHZ – 32kHz Output. This open-drain pin requires an external pullup resistor. It may be left open if not used.
- VCC – DC Power Pin for Primary Power Supply. This pin should be decoupled using a 0.1µF to 1.0µF capacitor. If not used, connect to ground.
- INT/SQW – ctive-Low Interrupt or Square-Wave Output. This open-drain pin requires an external pullup resistor. It may be left open if not used. This multifunction pin is determined by the state of the INTCN bit in the Control Register (0Eh). When INTCN is set to logic 0, this pin outputs a square wave and its frequency is determined by RS2 and RS1 bits. When INTCN is set to logic 1, then a match between the timekeeping registers and either of the alarm registers activates the INT/SQW pin (if the alarm is enabled). Because the INTCN bit is set to logic 1 when power is first applied, the pin defaults to an interrupt output with alarms disabled.
- RST – Active-Low Reset. This pin is an open-drain input/output. It indicates the status of VCC relative to the VPF specification. As VCC falls below VPF, the RST pin is driven low. When VCC exceeds VPF, for tRST, the RST pin is driven high impedance. The active-low, open-drain output is combined with a debounced pushbutton input function. This pin can be activated by a pushbutton reset request. It has an internal 50kΩ nominal value pullup resistor to VCC. No external pullup resistors should be connected. If the crystal oscillator is disabled, the startup time of the oscillator is added to the tRST delay.
- N.C. – No Connection. Must be connected to ground.
- GND – ground
- VBAT – Backup Power-Supply Input. This pin should be decoupled using a 0.1µF to 1.0µF low-leakage capacitor.If the I2C interface is inactive whenever the device is powered by the VBAT input, the decoupling capacitor is not required. If VBAT is not used, connect to ground. UL recognized to ensure against reverse charging when used with a lithium battery.
- SDA – Serial Data Input/Output. This pin is the data input/output for the I2C serial interface. This open-drain pin requires an external pullup resistor.
- SCL – Serial Clock Input. This pin is the clock input for the I2C serial interface and is used to synchronize data movement on the serial interface.