DA7217 datasheet(49/171 Pages) DIALOG

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DA7217

Ultra-Low Power Stereo Codec

Datasheet

Revision 2.5

01 Sep 2016

CFR0011-120-00

49 of 171

threshold above which the noise gate deactivates can be set in the same range using

dac_ng_off_threshold.

It is recommended to set dac_ng_off_threshold > dac_ng_on_threshold to provide some hysteresis.

The number of samples for which the DAC output signal must be below the on-threshold before the

noise gate is activated can be set to 256, 512, 1024 or 2048 using dac_ng_setup_time. The noise

gate is deactivated as soon as the signal level rises above the off threshold.

Prior to muting the output the gain is ramped down to minimum, and after un-muting the output the

gain is ramped back up to its original value. The ramp rates can be adjusted using

dac_ng_rampdn_rate and dac_ng_rampup_rate.

9.3.5.7

Digital Mixer

The DA7217 codec contains a flexible digital mixer. Any or all of the seven digital inputs (four input

filters, one tone generator, and two DAI inputs) can be routed to any or all of the six digital outputs

(Output Filter 1 and Output Filter 2, and four DAI outputs) with a programmable gain on each of the

42 possible paths.

The names of the registers that specify the data source, and the data output, take the form

‘<output target short name>_src’. Each of these 7-bit registers uses one of its bit positions to

select a signal source. These registers and the bit positions corresponding to each of the seven

possible signal source are listed in Table 39.

Example: Setting outdai_1l_src[2] = 1 selects source data from Input Filter 2L (determined by bit

position [2]) and passes it to Output DAI 1L.

The gain on each of the 42 signal paths (seven possible inputs to six possible outputs) are

independently controllable using registers whose names take the form

‘<output target short name>_<input source short name>_gain’. These register fields are listed

in Table 40. Every register field uses the same set of settings to provide a gain range of -42 dB to

4.5 dB in -1.5 dB steps. The full set of possible gain settings for each register is listed in Table 41.

Example: Setting outdai_1l_infilt_2r_gain = 01001 provides -28.5 dB gain on the signal path Input

Filter 2L to Output DAI 1L.

See Figure 23.for the input-to-output paths

DA7217 Datasheet(PDF) 49 Page - Dialog Semiconductor