PEF 20954 HT V1.1 Infineon Technologies, PEF 20954 HT V1.1 Datasheet - Page 115

• Manufacturer Part Number: PEF 20954 HT V1.1
• Description: IC ECHO CANCELLER DGTL TQFP144
• Manufacturer: Infineon Technologies

Specifications of PEF 20954 HT V1.1

• Function: Smart Integrated Digital Echo Canceller (SIDEC)
• Interface: PCM, Serial, UCC
• Number Of Circuits: 1
• Voltage - Supply: 3 V ~ 3.6 V
• Current - Supply: 350mA
• Power (watts): 900mW
• Operating Temperature: 0°C ~ 70°C
• Mounting Type: Surface Mount
• Package / Case: 144-LFQFP
• Includes: Double Talk Detection
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Other names: PEF20954HTV1.1; SP000007505

AVDCI[7:0] (Addr.: 75H): AFI Voice Detection Count Init, write protected,
Reset value = 85H
VDCI[7:0]
ATMAT[3:0] (Addr.: 77H): AFI Turbo Mode Activation Threshold, write protected,
Reset value = 08H
TURBOTH[3:0]
AACSC[7:0] (Addr.: 78H): AFI Auxiliary Coefficient Supervision Configuration,
write protected, Reset value = 00H
To improve handling of periodic signals, two thresholds are used to determine when
- probably due to a periodic signal - most of the auxiliary coefficients are becoming quite
large. In that case, coefficient update should be slowed down. The slow down mode
condition is described by ACSCTH[4:0] and ACSTH[1:0]. The effect of the slow down
mode can be configured via the bit ACSEFFECT.
Data Sheet
EFFECT
VDCI
ACS
[7]
-
ACSC
TH[4]
VDCI
[6]
-
Voice Detection Counter Init value:
A counter is used to count the number of values within the
VDINTERVAL which fulfill the "no-voice"-criterion. "no-voice" is
detected, if the counter ends up with a value that is greater or equal
to 512 (64 ms mode) or 1024 (128 ms mode), respectively. The init
-value for this counter is determined by VDCI in the following way:
64 ms Mode:
128 ms Mode:
The reset value of 85H requires that 48% of the values
must fulfill the "no-voice" criterion in case the default VDINTERVAL
(64 ms) is set)
Turbo Threshold:
This register specifies the threshold for activating the AFI turbo mode
(turbo-on indicates that the AFI is adapting to a new end echo path).
Turbo mode is activated if the absolute value of one or more auxiliary
coefficents is greater than 351 + 4 * TURBOTH.
The default threshold is 383.
ACSC
TH[3]
VDCI
[5]
-
,
ACSC
TH[2]
VDCI
[4]
-
115
<init-value> = VDCI[7..0] * 2
<init-value> = VDCI[7..0] * 4
TURBO
ACSC
VDCI
TH[3]
TH[1]
[3]
TURBO
ACSC
TH[2]
TH[0]
VDCI
[2]
Register Description
TURBO
TH[1]
TH[1]
VDCI
ACS
[1]
Rev. 2, 2004-07-28
PEB 20954
PEF 20954
TURBO
VDCI
TH[0]
TH[0]
ACS
[0]