The LP3943 takes incoming data from the baseband controller and feeds them into several registers that control the frequency and the duty cycle of the LEDs. Two prescaler registers and two PWM registers provide two individual rates to dim or blink the LEDs (for more information on these registers, refer to Table 6-1). Each LED can be programmed in one of four states: ON, OFF, DIM0 rate, or DIM1 rate. Two read-only registers provide status on all 16 LEDs. The LP3943 can be used to drive RGB LEDs and/or single-color LEDs to create a colorful, entertaining, and informative setting. Alternatively, it can also drive RGB LED as a flashlight. This is particularly suitable for accessory functions in cellular phones and toys. Any LED pins not used to drive LED can be used for general purpose parallel input/output (GPIO) expansion.

The LP3943 is equipped with power-on reset that holds the chip in a reset state until V_DD reaches V_POR during power up. Once V_POR is achieved, the LP3943 comes out of reset and initializes itself to the default state.

To bring the LP3943 into reset, hold the RST pin LOW for a period of TW. This puts the chip into its default state. The LP3943 can only be programmed after RST signal is HIGH again.