CS4205_05 Datasheet, PDF (49/81 Pages) Cirrus Logic – CrystalClear® Audio Codec ’97 for Portable Computing

CS4205
5.33 Signal Processing Engine Control Register (Index 6Eh, Address 08h)
D15 D14 D13 D12 D11 D10 D9 D8 D7 D6 D5 D4 D3 D2 D1 D0
Res SDI1M SRZC1 SRZC0 LPFS1 LPFS0 HPFS1 HPFS0 GL3 GL2 GL1 GL0 GR3 GR2 GR1 GR0
SDI1M
Serial Data Input 1 Mode. The SDI1M bit controls the flow of data from the first serial data input
into the signal processing engine. If this bit is ‘0’, the two channels of the SDI1 port are routed to
their respective channels of the SDI1 volume control. If this bit is ‘1’, the left channel of the SDI1
port is routed to both, the left and right channels of the SDI1 volume control.
SRZC[1:0]
Soft Ramp and Zero Cross Control. The SRZC bits control when changes take effect on the dig-
ital volume controls. Table 19 lists the available settings.
LPFS[1:0]
Low Pass Filter Select. The LPFS[1:0] bits select the center frequency of the low pass filter for
the EQ algorithm. Table 19 lists the available settings.
HPFS[1:0]
High Pass Filter Select. The HPFS[1:0] bits select the center frequency of the high pass filter for
the EQ algorithm. Table 19 lists the available settings.
GL[3:0]
Effects Engine Left Output Volume. The GL[3:0] bits are used to control the effects engine left
channel output volume. Each step corresponds to 1 dB gain adjustment, with 0000 = 0 dB atten-
uation. The total range is 0 dB to -15 dB attenuation.
GR[3:0]
Effects Engine Right Output Volume. The GR[3:0] bits are used to control the effects engine right
channel output volume. Each step corresponds to 1 dB gain adjustment, with 0000 = 0 dB atten-
uation. The total range is 0 dB to -15 dB attenuation.
Default
1800h
If the digital effects engine signals an overflow condition by setting the ELOF or EROF bit in the IEC Status Register
(Index 6Eh, Address 0B), the controller should correct the error by reducing the effects engine output volume in this
register.
SRZC[1:0]
LPFS[1:0]
HPFS[1:0]
00
01
10
11
Volume Change Mode
immediately
on zero crossings
soft ramp (1/8 dB step per frame)
1/8 dB step per zero crossing
Low Pass
Filter
20 Hz
50 Hz
100 Hz
reserved
High Pass
Filter
10 kHz
15 kHz
20 kHz
reserved
Table 19. Volume Change Modes and EQ Filter Selects
DS489PP4
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