BT8375 CONEXANT [Conexant Systems, Inc], BT8375 Datasheet - Page 163

• Manufacturer Part Number: BT8375
• Description: single chip transceivers for T1/E1 and Integrated Service Digital Network (ISDN) primary rate interfaces
• Manufacturer: CONEXANT [Conexant Systems, Inc]

Bt8370/8375/8376
Fully Integrated T1/E1 Framer and Line Interface
VGA[5:0]
N8370DSE
029—Variable Gain Amplifier Status
Line Attenuation
VGA Gain
—
7
Indicates the current VGA gain level. The processor must write to this register (any value)
before reading it to allow internal latches to update. The internal VGA has 64 gain values with
code value 0x3F (63 dec) equal to maximum gain. The processor can estimate the line
attenuation (or received signal level) in dB relative to a 3 V peak pulse level, according to the
following table:
—
0x0F
6
0
Figure 3-1. Receive Equalizer Eye Pattern Output
0x1C
VGA[5]
10
5
or:
0.77 dB/step—under 10 dB
1.25 dB/step—10
1.67 dB/step—40
2.80 dB/step—50 dB
ADDRESS 028 - EQ OUTPUT LEVEL (EQ_OUT)
0x23
20
VGA[4]
4
Pulse Height
Pulse Height
Conexant
Negative
Positive
–
–
40 dB
50 dB
0x2B
30
VGA[3]
3
0x34
Tolerance
Tolerance
40
± Error
± Error
± Full Scale
VGA[2]
2
0x3A
50
VGA[1]
3.7 Receive LIU Registers
1
0x3D
60
0x3F (max)
VGA[0]
64dB
0
3-45