8.3.5.3 Real-Time Playback (RTP) Interface

The real-time playback mode is a simple, single 8-bit register interface that holds an amplitude value. When real-time playback is enabled, the real-time playback register is sent directly to the playback engine. The amplitude value is played until the user sends the device to standby mode or removes the device from RTP mode. The RTP mode operates exactly like the PWM mode except that the user enters a register value over the I²C rather than a duty cycle through the input pin. Therefore, any API (application-programming interface) designed for use with a PWM generator in the host processor can write the data values over the I²C rather than writing the data values to the host timer. This ability frees a timer in the host while retaining compatibility with the original software.

For the LRA, the DRV2605L device automatically tracks the resonance frequency unless the LRA_OPEN_LOOP bit is set (in register 0x1D). If the LRA_OPEN_LOOP bit is set, the LRA is driven according to the open-loop frequency set in the OL_LRA_PERIOD[6:0] bit in register 0x20.