XRT72L50 Datasheet, PDF (191/471 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
FIGURE 53. 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
R xC lk
RxFram e
R xL O S
R xO O F
R xR E D
R xA IS
U1
45
43
TxS er/S n d M sg
61
TxIn C lk
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
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
M O TO
86
88 ^RxSer/RxIdle
90
R xC lk
RxFram e
95
94
R xL O S
93
R xO O F
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
RxPO 76
S
RxNE 75
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
TRIN
G
8
RTIP
9
RRING
C1
1
2
0.01uF
R5
37.5
R6
37.5
1 T2
5
4
8
1:1
RTI
P
RRIN
G
The Transmit Section of the XRT72L50 contains a block which is known as the Transmit DS3 LIU Interface
block. The purpose of the Transmit DS3 LIU Interface block is to take the outbound DS3 data stream, from the
Transmit DS3 Framer block, and to do the following:
1. Encode this data into one of the following line codes
a. Unipolar (e.g., Single-Rail)
b. AMI (Alternate Mark Inversion)
c. B3ZS (Bipolar 3 Zero Substitution)
2. And to transmit this data to the LIU IC.
Figure 54 presents a simple illustration of the Transmit DS3 LIU Interface block.
FIGURE 54. THE TRANSMIT DS3 LIU INTERFACE BLOCK
From Transmit DS3
Framer Block
Transmit
DS3 LIU
Interface Block
TxPOS
TxNEG
TxLineClk
178