
XRT72L50
SINGLE CHANNEL DS3/E3 FRAMER IC WITH HDLC CONTROLLER
REV. P1.1.3
á
PRELIMINARY
XII
II/O C
ONTROL
R
EGISTER
(A
DDRESS
= 0
X
01) ......................................................................................... 286
T
ABLE
58: T
HE
R
ELATIONSHIP
BETWEEN
THE
CONTENTS
OF
B
IT
2 (T
X
L
INE
C
LK
I
NV
)
WITHIN
THE
I/O C
ONTROL
R
EGISTER
AND
THE
T
X
L
INE
C
LK
CLOCK
EDGE
THAT
T
X
POS
AND
T
X
NEG
ARE
UPDATED
ON
..................... 287
Figure 125. Waveform/Timing Relationship between TxLineClk, TxPOS and TxNEG - TxPOS and TxNEG
are configured to be updated on the rising edge of TxLineClk ............................................................ 287
Figure 126. Waveform/Timing Relationship between TxLineClk, TxPOS and TxNEG - TxPOS and TxNEG
are configured to be updated on the falling edge of TxLineClk ........................................................... 288
5.2.6 Transmit Section Interrupt Processing .................................................................................................. 288
B
LOCK
I
NTERRUPT
E
NABLE
R
EGISTER
(A
DDRESS
= 0
X
04) ...................................................................... 288
T
X
E3 LAPD S
TATUS
AND
I
NTERRUPT
R
EGISTER
(A
DDRESS
= 0
X
34) ...................................................... 289
T
X
E3 LAPD S
TATUS
AND
I
NTERRUPT
R
EGISTER
(A
DDRESS
= 0
X
34) ...................................................... 289
5.3 T
HE
R
ECEIVE
S
ECTION
OF
THE
XRT72L50 (E3 M
ODE
O
PERATION
) .................................................................... 289
Figure 127. A Simple Illustration of the Receive Section of the XRT72L50 configured to operate in the E3
Mode .................................................................................................................................................... 290
5.3.1 The Receive E3 LIU Interface Block ...................................................................................................... 290
Figure 128. A Simple Illustration of the Receive E3 LIU Interface Block ............................................ 291
Figure 129. Behavior of the RxPOS, RxNEG and RxLineClk signals during data reception of Unipolar Data
291
I/O C
ONTROL
R
EGISTER
(A
DDRESS
= 0
X
01) .......................................................................................... 292
T
ABLE
59: T
HE
R
ELATIONSHIP
BETWEEN
THE
CONTENTS
OF
B
IT
2 (T
X
L
INE
C
LK
I
NV
)
WITHIN
THE
I/O C
ONTROL
R
EGISTER
AND
THE
T
X
L
INE
C
LK
CLOCK
EDGE
THAT
T
X
POS
AND
T
X
NEG
ARE
UPDATED
ON
..................... 292
Figure 130. Illustration on how a Channel of the Receive E3 Framer (within the XRT72L50 Framer IC) being
interface to theXRT73L00 Line Interface Unit, while operating in Bipolar Mode ................................. 293
Figure 131. Illustration of AMI Line Code ........................................................................................... 294
Figure 132. Illustration of two examples of HDB3 Decoding .............................................................. 294
II/O C
ONTROL
R
EGISTER
(A
DDRESS
= 0
X
01) ......................................................................................... 295
T
ABLE
60: T
HE
R
ELATIONSHIP
BETWEEN
THE
CONTENTS
OF
B
IT
1 (R
X
L
INE
C
LK
I
NV
)
OF
THE
I/O C
ONTROL
R
EG
-
ISTER
,
AND
THE
SAMPLING
EDGE
OF
THE
R
X
L
INE
C
LK
SIGNAL
................................................................... 295
Figure 133. Waveform/Timing Relationship between RxLineClk, RxPOS and RxNEG - When RxPOS and
RxNEG are to be sampled on the rising edge of RxLineClk ................................................................ 296
Figure 134. Waveform/Timing Relationship between RxLineClk, RxPOS and RxNEG - When RxPOS and
RxNEG are to be sampled on the falling edge of RxLineClk ............................................................... 296
5.3.2 The Receive E3 Framer Block ............................................................................................................... 296
Figure 135. A Simple Illustration of the Receive E3 Framer Block and the Associated Paths to the Other
Functional Blocks ................................................................................................................................ 297
Figure 136. The State Machine Diagram for the Receive E3 Framer E3 Frame Acquisition/Maintenance Al-
gorithm ................................................................................................................................................. 298
Figure 137. Illustration of the E3, ITU-T G.751 Framing Format ........................................................ 298
R
X
E3 I
NTERRUPT
S
TATUS
R
EGISTER
- 1 (A
DDRESS
= 0
X
14) .................................................................. 299
R
X
E3 C
ONFIGURATION
& S
TATUS
R
EGISTER
- 2 (A
DDRESS
= 0
X
11) ....................................................... 300
R
X
E3 I
NTERRUPT
TATUS
R
EGISTER
- 1 (A
DDRESS
= 0
X
14) .................................................................. 300
R
X
E3 I
NTERRUPT
S
TATUS
R
EGISTER
- 1 (A
DDRESS
= 0
X
14) .................................................................. 300
R
X
E3 C
ONFIGURATION
& S
TATUS
R
EGISTER
- 2 (A
DDRESS
= 0
X
11) ....................................................... 301
PMON F
RAMING
B
IT
/B
YTE
E
RROR
C
OUNT
R
EGISTER
- MSB (A
DDRESS
= 0
X
52) ................................... 301
PMON F
RAMING
B
IT
/B
YTE
E
RROR
C
OUNT
R
EGISTER
- LSB (A
DDRESS
= 0
X
53) .................................... 301
R
X
E3 C
ONFIGURATION
& S
TATUS
R
EGISTER
- 2 (A
DDRESS
= 0
X
11) ....................................................... 302
T
ABLE
61: T
HE
R
ELATIONSHIP
BETWEEN
THE
L
OGIC
S
TATE
OF
THE
R
X
OOF
AND
R
X
LOF
OUTPUT
PINS
,
AND
THE
F
RAMING
S
TATE
OF
THE
R
ECEIVE
E3 F
RAMER
BLOCK
............................................................................ 302
R
X
E3 C
ONFIGURATION
& S
TATUS
R
EGISTER
- 2 (A
DDRESS
= 0
X
11) ....................................................... 303
R
X
E3 I
NTERRUPT
S
TATUS
R
EGISTER
- 1 (A
DDRESS
= 0
X
14) .................................................................. 303
R
X
E3 C
ONFIGURATION
& S
TATUS
R
EGISTER
- 2 (A
DDRESS
= 0
X
11) ....................................................... 303
R
X
E3 I
NTERRUPT
S
TATUS
R
EGISTER
- 1 (A
DDRESS
= 0
X
14) .................................................................. 304
R
X
E3 C
ONFIGURATION
& S
TATUS
R
EGISTER
- 2 (A
DDRESS
= 0
X
11) ....................................................... 304
R
X
E3 C
ONFIGURATION
& S
TATUS
R
EGISTER
- 2 (A
DDRESS
= 0
X
11) ....................................................... 304
R
X
E3 C
ONFIGURATION
& S
TATUS
R
EGISTER
- 1 G.751 (A
DDRESS
= 0
X
10) ............................................ 305