WM8946ECSSLASHR datasheet(38/175 Pages) WOLFSON

38 / 175 page

WM8946

Production Data

PD, July 2012, Rev 4.3

To determine the characteristics of the microphone in an application, a test signal is applied to a

loudspeaker that is in the acoustic path to the microphone. The received signal through the

application microphone is analysed and compared with the received signal from a reference

microphone in order to determine the characteristics of the application microphone.

To determine the characteristics of the loudspeaker in an application, a test signal is applied to the

target application. A reference microphone is positioned in the normal acoustic path of the

loudspeaker, and the received signal is analysed to determine how accurately the loudspeaker has

reproduced the test signal.

5-BAND EQ

ReTuneTM

5-band EQ

Signal Enhancement Block 2 (SE2)

The 5-band EQ is part of the SE2 block. This function allows 5 frequency bands to be controlled. The

upper and lower frequency bands are controlled by low-pass and high-pass filters respectively. The

middle three frequency bands are notch filters. The cut-off / centre frequency of each filter is

programmable, and up to 12dB gain or attenuation can be selected in each case. The left and right

channel parameters may be programmed individually. The 5-band EQ may be enabled using the

SE2_5BEQ_L_ENA register bit defined in Table 14. For the derivation of the other associated

registers, refer to the WISCE software.

Note that when the right channel 5BEQ filter is disabled the gains for each of the frequency

bands must be set to 0dB.

Typical applications of the 5-band EQ include the selection of user-preferences for different music

types, such as ‘rock’, ‘dance’ or ‘classical’ EQ profiles.

DYNAMIC RANGE CONTROL (DRC)

DRC

Signal Enhancement Block 3 (SE3)

The Dynamic Range Control (DRC) forms the SE3 block. The DRC provides a range of compression,

limiting and noise gate functions to support optimum configuration for recording or playback modes.

The DRC is configured using the control fields in registers R29 to R35 - see “Dynamic Range

Control”.

SIGNAL ENHANCEMENT REGISTER CONTROLS

The SE1 ‘enable’ bits are described in Table 13. Note that other control fields must also be

determined and written to the WM8946 using WISCE™ or other tools. The registers described below

only allow the sub-blocks of SE1 to be enabled or disabled.

Note that it is not recommended to access these control fields unless appropriate values have been

written to the associated bits in registers R65 to R98.

WM8946ECS/R Datasheet(PDF) 38 Page - Wolfson Microelectronics plc