Datasheet

0x00
0x7FF
ERM Library A
LibrarySel = 1
ERM Library E
LibrarySel = 5
LRA Library
LibrarySel = 6
Auxillary Library
{Empty}
LibrarySel = 7
DRV2605
SLOS825B –DECEMBER 2012–REVISED JANUARY 2014 www.ti.com
WAVEFORM LIBRARIES
The DRV2605 has 6 internal ROM libraries designed by Immersion called TS2200. These first five libraries are
specifically tuned for 5 categories of ERM motors in the open loop mode of operation. Library 6 is tuned for LRA
devices. Auxiliary library 7 currently contains no information, but may be populated with other libraries in future
device revisions.
WAVEFORM SEQUENCER
The waveform sequencer (See registers 0x04 to 0x0B) is used to queue waveform library identifiers for playback.
There are eight sequence registers to queue up to eight library waveforms for sequential playback. A waveform
identifier is an integer value referring to the index position of a waveform in a ROM library. Playback begins at
register address 0x04 when the user asserts the GO bit (Register 0x0C). When playback of that waveform ends,
the waveform sequencer plays the next waveform identifier held in register 0x05, if it is non-zero. The waveform
sequencer continues in this fashion until it reaches an identifier value of zero, or all eight identifiers are played
(register addresses 0x04 through 0x0B), whichever comes first.
The waveform identifier range is 1 to 127. The MSB of each sequence register may be used to implement a
delay between sequence waveforms. When the MSB is high, bits [6:0] are used to indicate the length of the wait
time. The wait time for that step then becomes WavfrmSeq[6:0] × 10 milliseconds.
LIBRARY PARAMETERIZATION
The ROM libraries will be augmented by the following 8-bit values in the register map. This parameterization will
take place only for the ROM libraries and not for the other interfaces (e.g. PWM, RTP). The purpose of this
functionality is to add “time stretching” (or time shrinking) parameters to the playback. This can be useful for
customizing the entire library of waveforms for a specific actuator rise time and fall time.
ODT: Overdrive Time
SPT: Sustain Positive Time
SNT: Sustain Negative Time
BRT: Brake Time
The time values are additive offsets and are 8-bit signed values. These values are 0 offset by default. Positive
values add, and negative values subtract from the “Time” value of the effect that is currently being played. The
most positive value in the waveform is automatically interpreted as the overdrive time, and the most negative
value in the waveform is automatically interpreted as the brake time. These time offset parameters are applied to
both Voltage/Time pairs and linear ramps. For linear ramps, linear interpolation is shrunken/stretched over the
two operative points for the period Time+TimeOffset, where TimeOffset is one of the time parameters listed
above.
REAL-TIME PLAYBACK (RTP) MODE
The real time playback mode is a simple, single 8-bit register interface that holds an amplitude value. It is
enabled by selecting RTP Mode in the Mode register. Once real-time playback is enabled, the real-time playback
register will be sent directly to the playback engine. This value is played until the user sets device in STANDBY
mode or exits RTP mode. The RTP mode operates exactly like the PWM mode, except the user is entering a
register value over I
2
C rather than a duty cycle via the input pin; therefore, any API designed to use a PWM
generator in the host processor can write the data values over I2C rather than writing the data values to the host
timer. This frees a timer in the host while retaining compatibility with the original software.
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