AN2834 Freescale Semiconductor / Motorola, AN2834 Datasheet - Page 9

• Manufacturer Part Number: AN2834
• Description: AN2834, Packet Telephony Automatic Level Control on the StarCore SC140 Core
• Manufacturer: Freescale Semiconductor / Motorola

Figure 4 shows the dynamic signal levels and total gain g
where the target reference level is set to P
4
All the objective tests reported in Table 2 were performed on the DSPG ECT-1 ALC tester equipment with a T1
connection. The test coverage follows the ITU-T G.169 specification [6]. Because the ALC device is designed as a
step-gain device, the Test 7.4.1 method 1 is not applicable. For this test, method 2 was used and it demonstrated the
expected performance; that is, no degradation occurred after the ALC device was inserted into the system. Also,
Tests 7.5.1 and 7.5.2 are not included here because they are not implemented in the ECT-1 ALC tester equipment.
Freescale Semiconductor
G.169 Compliance Test Results
Test 7.1.2A
Test 7.1.2B
Test 7.1.2C
Test 7.2B
Test 7.3A
Test 7.3B
–10
–15
–10
–20
–30
–40
–50
Packet Telephony Automatic Level Control on the StarCore SC140 Core, Rev. 1
–5
DSPG Test ID
5
0
0
0
0
0.1
0.1
Figure 4. Dynamic Signal Levels and Total Gain
0.2
0.2
Dynamic Signal Level Change (P
Table 2. G.169 Test Coverage
ref
0.3
0.3
= –16 dBm0.
Stability test with echo cancellation. Derive initial gain.
Stability test with echo cancellation. Maximum gain in 1 second.
Stability test with echo cancellation. Maximum gain.
Echo robustness test with echo cancellation.
Noise tolerance test. Robustness to circuit noise.
Noise tolerance test. Robustness to environment noise.
Dynamic Gain Adaptation
0.4
0.4
Time (s)
Time (s)
0.5
0.5
t
(n) corresponding to the signals illustrated in Figure 3,
0.6
0.6
G.169 Test Name
ref
= –16 dBm0
0.7
0.7
0.8
0.8
G.169 Compliance Test Results
0.9
0.9
1
1
9