TWR-AUDIO-SGTL Freescale Semiconductor, TWR-AUDIO-SGTL Datasheet - Page 21

• Manufacturer Part Number: TWR-AUDIO-SGTL
• Description: TWR SYS Audio Board
• Manufacturer: Freescale Semiconductor
• Series: Kinetisr

Specifications of TWR-AUDIO-SGTL

• Kit Contents: TWR-AUDIO-SGTL Featuring SGTL5000 Low Power Stereo Codec, Printed Quick Start Guide
• Mcu Supported Families: K20, K50, MCF51Jx
• Kit Features: SGTL5000 Low Power Stereo Codec With Headphone
• Rohs Compliant: Yes
• Design Resources: TWR-AUDIO-SGTL Schematics
• Accessory Type: Module, Audio with CODEC
• Description/function: Audio CODECs
• Mounting Style: Press Fit
• Product: Audio Modules
• Features: SGTL5000 Low Power Stereo Codec With Headphone Amplifier, Stereo Line-in / Line-out On 3.5mm Jack
• Lead Free Status / Rohs Status: Details
• For Use With/related Products: Freescale Tower System

then a value of 0.5 should be put in b
coefficients should be set to 0.0. Note that the coefficients
must be converted to hex values before writing to the
registers. By default, all the filters are loaded with coefficients
to give a flat response.
Classical, etc, the coefficients must be calculated, converted
to 20-bit hex values and written to the registers. Note that
coefficients are sample-rate dependent and separate
coefficients must be generated for different sample rates.
Please contact Freescale for assistance with generating the
coefficients.
example that shows how load the filter coefficients when the
end-user changes the preset.
DAP_AUDIO_EQ->EN bits.
5-Band Graphic EQ
parallel second order IIR filters. All filters are implemented
using biquad filters whose coefficients are programmed to set
the bands at specific frequency. The GEQ bands are fixed at
Analog Integrated Circuit Device Data
Freescale Semiconductor
If a band is enabled but is not being used (flat response),
In order to create EQ presets such as Rock, Speech,
Refer to
PEQ can be disabled (pass-through mode) by writing 0 to
The 5-band graphic equalizer is implemented using 5
7-Band PEQ Preset Selection
X(z)
z
z
−
−
1
1
Figure 15. 5-Coefficient Biquad Filter and Transfer Function
0
and all other
for a programming
b
b
b
0
1
2
H
(
z
)
=
Direct Form 1
b
1
0
+
∑
+
a
b
1
1
z
z
−
−
1
115 Hz, 330 Hz, 990 Hz, 3000 Hz, and 9900 Hz. The volume
on each band is independently adjustable in the range of
+12 dB to -11.75 dB in 0.25 dB steps.
example that shows how to change the GEQ volume.
Tone Control
control is implemented as one 2nd order low pass filter (bass)
and one 2nd order high pass filter (treble).
programming example that shows how to change Bass and
Treble values.
Automatic Volume Control (AVC)
reduce loud signals and amplify low level signals for easier
listening. The AVC is designed to compress audio when the
measured level is above the programmed threshold or to
expand the audio to the programmed threshold when the
measured audio is below the threshold. The threshold level is
programmable with allowed range of 0 to -96 dB.
shows the AVC block diagram and controls.
1
+
+
Refer to
Tone control comprises treble and bass controls. The tone
Refer to
An Automatic Volume Control (AVC) block is provided to
a
b
2
2
z
z
−
−
2
2
-a
-a
5-Band GEQ Volume Change
Tone Control - Bass and Treble Change
1
2
FUNCTIONAL INTERNAL BLOCK DESCRIPTION
z
z
FUNCTIONAL DEVICE OPERATION
−
−
1
1
H(z)X(z)
for a programming
Figure 16
SGTL5000
for a
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