PCT2303N DATA SHEET
CONTROL REGISTERS
!!
Miscellaneous Modem AFE Status and Control
(Register 56h, R/W)
Reserved
MLNK
Reserved
L2B[2:0]
R
L1B[2:0]
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
Reset settings = 0000h
This read/write register defines the loopback modes available for the modem line ADCs/DACs. The default value
after cold register reset (0000h) is all loopbacks disabled.
Bit Definitions:
Bits
15:13
Name
Description
Reserved
MLNK
Reserved. Read returns zero.
12
Controls an MC’97’s AC-link status.
1 = Sets the MC’97 AC-link to off (sleep).
0 = Sets the MC’97 AC-link to on (active).
11:7
6:4
Reserved
L2B[2:0]
Reserved. Read returns zero.
Line 2 loopback modes.
L2B[2:0]
000
Description
Disabled (default).
001
ADC loopback (I’B).
010
Local analog loopback (F’M).
Digital DAC loopback (C’J).
Remote analog loopback (M’’F).
Isolation Cap loopback (D’K).
External analog loopback (G’N).
Reserved.
011
100
101
110
111
3
Reserved
L1B[2:0]
Reserved. Read returns zero.
Line 1 loopback modes.
2:0
L1B[2:0]
000
Description
Disabled (default).
001
ADC loopback (I’B).
010
Local analog loopback (F’M).
Digital DAC loopback (C’J).
Remote analog loopback (M’F).
Isolation Cap loopback (D’K).
External analog loopback (G’N).
Reserved.
011
100
101
110
111
303A
303L
D
C
J
A
H
E
F
G
N
B
DAC
Output
Digital
Filter
I/O
Pad
Analog
DAC
AC
Link
K
L
M
I
Digital
Filter
ADC
Input
Analog
ADC
I/O
Pad
NOTE: For all loopback modes except 011, line side must be powered on and off-hook.
Figure 10 Loopback Points
PC-TEL, Inc.
23
2303N0DOCDAT10A-0899
ETC [ ETC ]
