Version: 1.18
PRELIMINARY/CONFIDENTIAL
TrueSpeech® Co-Processor
To enable all 4 filters the following command sequence can be used:
Command
5154H
5153H
5155H
5153H
5156H
5153H
5157H
5153H
Status Response
5154H
Action
Select Filter F0
Filter F0 is enabled
Select Filter F1
Filters F1+F0 are enabled
Select Filter F2
Filters F2+F1+F0 are enabled
Select Filter F3
0001H
5155H
0003H
5156H
0007H
5157H
000FH
Filters F3+F2+F1+F0 are enabled
9.20.5
Reading the Filter Energy Output
It is possible to read the actual Filter Energy output values using the following command (516XH):
0101
0001
0110
(7-4)
FILTER
(3-2)
INDEX
(1-0)
(15-12)
(11-8)
FILTER:
INDEX:
00
01
10
11
F0
F1
F2
F3
00
01
10
11
Broadband Energy ls word (bits 15-0)
Broadband Energyms word (bits 31-16)
In Band Energy ls word (bits 15-0)
In Band Energyms word (bits 31-16)
The status response contains the 16-bit value selected by INDEX.
Each filter provides two 32-bit energy parameters:
•
•
The broadband energy of the un-filtered input signal.
The in-band energy at the filter output.
The energy value is calculated over a 240 sample (30ms) input frame:
Energy = 1/32 * ∑ (x/4) * (x/4)
If more than one filter is enabled, the broadband energy from each enabled filter will be the same.
CT8022A11AQC FW Revision 0118 DSP GROUP, INC., 3120 SCOTT BOULEVARD
SANTA CLARA, CA 95054 PH: 408 986 – 4300 FAX: 408 986 – 4490
133
All specifications are subject to change without prior notice.
ETC [ ETC ]
