XRT72L50 Datasheet, PDF (409/471 Pages) Exar Corporation – SINGLE CHANNEL DS3/E3 FRAMER IC WITH HDLC CONTROLLER

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XRT72L50
SINGLE CHANNEL DS3/E3 FRAMER WITH HDLC CONTROLLER
REV. 1.2.1
I/O Control Register (Address = 0x01)
BIT 7
Disable
TxLOC
R/W
1
BIT 6
LOC
RO
0
BIT 5
Disable
RxLOC
R/W
1
BIT 4
AMI/ZeroSup
R/W
0
BIT 3
Unipolar/
Bipolar
R/W
0
BIT2
BIT 1
TxLine CLK RxLine CLK
Invert
Invert
R/W
R/W
0
0
Table 80 relates the value of this bit-field to the Receive E3 LIU Interface Input Mode.
BIT 0
Reframe
R/W
0
TABLE 80: THE RELATIONSHIP BETWEEN THE CONTENTS OF BIT 3 (UNIPOLAR/BIPOLAR) WITHIN THE I/O CONTROL
REGISTER
BIT 3
0
1
RECEIVE E3 LIU INTERFACE INPUT MODE
Bipolar Mode (Dual Rail): AMI or HDB3 Line Codes are Transmitted and Received.
Unipolar Mode (Single Rail) Mode of transmission and reception of E3 data is selected.
NOTES:
1. The default condition is the Bipolar Mode.
2. This selection also effects the Transmit E3 Framer Line Interface Output Mode.
6.3.1.2 Bipolar Decoding
If the Receive E3 LIU Interface block is operating in the Bipolar Mode, then it will receive the E3 data pulses via
both the RxPOS, RxNEG, and the RxLineClk input pins. Figure 176 presents a circuit diagram illustrating how
the Receive E3 LIU Interface block interfaces to the Line Interface Unit while the Framer is operating in Bipolar
mode. The Receive E3 LIU Interface block can be configured to decode either the AMI or HDB3 line codes.
FIGURE 176. INTERFACING THE XRT72L50 FRAMER IC TO THE XRT73L00 DS3/E3/STS-1 LIU
TxS E R
TxIn C lk
TxFram e
NIBBLEINTF
RESETB
INTB
CSB
RW
DS
AS
INTB
A[8:0]
D[7:0]
VDD
R xS er
RxCl
k
RxFram e
RxLO
S
R xO O F
RxRE
R xA ID
S
U1
45
43
TxS er/S n d M sg
61 ^TxInClk
TxFram e
25
N ib In tf
28
Reset
13
8 ^Int
7 ^CS
10 ^{W R_R/W}
9 ^RD_DS
6 ^ALE_AS
RDY_DTCK
15
A0
16
17 ^A1
18 ^A2
19 ^A3
20 ^A4
21 ^A5
22 ^A6
23 ^A7
A8
32
33 ^D0
34 ^D1
35 ^D2
36 ^D3
37 ^D4
38 ^D5
39 ^D6
D7
27
M O TO
86
88 ^RxSer/RxIdle
90 ^RxClk
RxFram e
95
94 ^RxLOS
93 ^RxOOF
87 ^RxRed
R xA IS
XRT72L50
65
TxP O S
64
TxN E G
63
TxL in eC lk
79
DMO
78
E xtL O S
77
RLOL
69
LLOOP
70
RLOOP
68
TA O S
67
TxLev
66
E n c oD is
71
Req
76
R xP O S
75
R xN E G
74
R xL in eC lk
U2
37
TPDATA
38
TNDATA
36
TCLK
4
DMO
24
RLOS
23
RLOL
14
LLB
15
RLB
2
TA O S
1
TxL E V
21
E N C O D IS
12
R E Q D IS
33
RPOS
32
RNEG
31
RCLK1
XRT73L00
41
TTIP
40
TRING
44
MTIP
43
MRING
1
R3
2
270
1
R4
2
270
R1
1
2
36
1 T1
5
R2
1
2
36
4
8
1:1
TTIP
TRING
8
RTIP
9
RRING
C1
1
2
0.01uF
R5
37.5
R6
37.5
1 T2
5
4
8
1:1
RTIP
RRING
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