RS8953 Conexant Systems, Inc., RS8953 Datasheet - Page 105

• Manufacturer Part Number: RS8953
• Description: High-bit-rate Digital Subscriber Line (hdsl) Channel unit
• Manufacturer: Conexant Systems, Inc.

RS8953B/8953SPB
HDSL Channel Unit
DPLL_GAIN[7:0]
N8953BDSB
0xD8—DPLL Gain (DPLL_GAIN)
Specific DC parameter values are programmed according to the following tables:
—
7
DPLL Gain—Filtering is controlled by two DC parameters: DC_GAIN, which represents
proportional loop gain, and DC_INTEG, which represents the filter’s integration coefficient.
The DPLL closed loop bandwidth is programmed to be in the range of 0.2 Hz to 3 Hz. The
following approximations are used to calculate DC parameters for a desired DPLL bandwidth:
6
DC_GAIN[2:0]
where:
5
DC_GAIN
DC_INTEG
BW = DPLL closed loop bandwidth (in Hz)
N = RCLK output frequency
4
Conexant
=
=
--------------------
N
--------------- -
26.5
BW
BW
26.5
2
2
DC_INTEG[3:0]
DC_GAIN[2:0]
3
1010–1110
2
------- -
2
N
0000
0001
0010
0011
0100
0101
0110
0111
1000
1001
1111
15
17
000
001
010
011
100
101
110
111
64000
2
DC_INTEG[3:0]
RS8953B
RS8953B
0 (Type I)
1
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
4.9 DPLL Configuration
1
10
11
12
–4
–3
–2
–1
5
6
7
8
9
1
2
3
4
5
6
4.0 Registers
0
4-37