XR72L52 Datasheet, PDF (205/480 Pages) Exar Corporation – TWO CHANNEL DS3/E3 FRAMER IC WITH HDLC CONTROLLER

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TWO CHANNEL DS3/E3 FRAMER IC WITH HDLC CONTROLLER
XRT72L52
REV. 1.0.1
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 32 relates the value of this bit-field to the Receive DS3 LIU Interface Input Mode.
BIT 0
Reframe
R/W
0
TABLE 32: THE RELATIONSHIP BETWEEN THE CONTENTS OF BIT 3 (UNIPOLAR/BIPOLAR) WITHIN THE I/O CONTROL
REGISTER AND THE TXLINECLK CLOCK EDGE THAT TXPOS AND TXNEG ARE UPDATED ON
BIT 3
0
1
RECEIVE DS3 LIU INTERFACE INPUT MODE
Bipolar Mode (Dual Rail): AMI or B3ZS Line Codes are Transmitted and Received.
Unipolar Mode (Single Rail) Mode of transmission and reception of DS3 data is selected.
NOTES:
1. The default condition is the Bipolar Mode.
2. This selection also effects the Transmit DS3 Framer Line Interface Output Mode
4.3.1.2 Bipolar Decoding
If the Receive DS3 LIU Interface block is operating in the Bipolar Mode, then it will receive the DS3 data pulses
via both the RxPOS, RxNEG, and the RxLineClk input pins. Figure 63 presents a circuit diagram illustrating
how the Receive DS3 LIU Interface block interfaces to the Line Interface Unit while the Framer is operating in
Bipolar mode. The Receive DS3 LIU Interface block can be configured to decode the incoming data from ei-
ther the AMI or B3ZS line codes.
FIGURE 63. IINTERFACING THE XRT72L52 FRAMER IC TO THE XRT73L00 DS3/E3/STS-1 LIU
TxSER
TxInClk
TxFrame
NIBBLEINTF
RESETB
INTB
CSB
RW
DS
AS
INTB
A[8:0]
D[7:0]
VDD
RxSer
RxClk
RxFrame
RxLOS
RxOOF
RxRED
RxAIS
U1
45
43
TxSer/SndMsg
61 ^TxInClk
TxFrame
25
NibIntf
28
Reset
13
8 ^Int
7 ^CS
10 ^WR_R/W
9 ^RD_DS
6 ^ALE_AS
RDY_DTCK
15
16 ^A0
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
MOTO
86
88 ^RxSer/RxIdle
90 ^RxClk
RxFrame
95
94 ^RxLOS
93 ^RxOOF
87 ^RxRed
RxAIS
XRT72L50
65
TxPOS
64
TxNEG
63
TxLineClk
79
DMO
78
ExtLOS
77
RLOL
69
LLOOP
70
RLOOP
68
TAOS
67
TxLev
EncoDis ⁶⁶
71
Req
76
RxPOS
75
RxNEG
74
RxLineClk
U2
37
TPDATA
38
TNDATA
36
TCLK
4
DMO
24
RLOS
23
RLOL
14
LLB
15
RLB
2
TAOS
1
TxLEV
21 _ENCODIS
12
REQDIS
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
189