
XRT72L52
TWO CHANNEL DS3/E3 FRAMER IC WITH HDLC CONTROLLER
REV. P1.1.3
á
PRELIMINARY
XII
I/O C
ONTROL
R
EGISTER
(A
DDRESS
= 0
X
01) .......................................................................................... 292
T
ABLE
58: T
HE
R
ELATIONSHIP
BETWEEN
B
IT
4 (AMI/HDB3*)
WITHIN
THE
I/O C
ONTROL
R
EGISTER
AND
THE
B
I
-
POLAR
L
INE
C
ODE
THAT
IS
OUTPUT
BY
THE
T
RANSMIT
E3 LIU I
NTERFACE
B
LOCK
.................................... 292
II/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 125. Waveform/Timing Relationship between TxLineClk, TxPOS and TxNEG - TxPOS and TxNEG
are configured to be updated on the rising edge of TxLineClk ............................................................ 293
Figure 126. Waveform/Timing Relationship between TxLineClk, TxPOS and TxNEG - TxPOS and TxNEG
are configured to be updated on the falling edge of TxLineClk ........................................................... 293
5.2.6 Transmit Section Interrupt Processing .................................................................................................. 293
B
LOCK
I
NTERRUPT
E
NABLE
R
EGISTER
(A
DDRESS
= 0
X
04) ...................................................................... 294
T
X
E3 LAPD S
TATUS
AND
I
NTERRUPT
R
EGISTER
(A
DDRESS
= 0
X
34) ...................................................... 294
T
X
E3 LAPD S
TATUS
AND
I
NTERRUPT
R
EGISTER
(A
DDRESS
= 0
X
34) ...................................................... 295
5.3 T
HE
R
ECEIVE
S
ECTION
OF
THE
XRT72L52 (E3 M
ODE
O
PERATION
) .................................................................... 295
Figure 127. A Simple Illustration of the Receive Section of the XRT72L52 configured to operate in the E3
Mode .................................................................................................................................................... 295
5.3.1 The Receive E3 LIU Interface Block ...................................................................................................... 295
Figure 128. A Simple Illustration of the Receive E3 LIU Interface Block ............................................ 296
Figure 129. Behavior of the RxPOS, RxNEG and RxLineClk signals during data reception of Unipolar Data
297
I/O C
ONTROL
R
EGISTER
(A
DDRESS
= 0
X
01) .......................................................................................... 297
T
ABLE
60: 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
..................... 297
Figure 130. Illustration on how a Channel of the Receive E3 Framer (within the XRT72L52 Framer IC) being
interface to theXRT7302 Line Interface Unit, while operating in Bipolar Mode ................................... 298
Figure 131. Illustration of AMI Line Code ........................................................................................... 299
Figure 132. Illustration of two examples of HDB3 Decoding .............................................................. 299
II/O C
ONTROL
R
EGISTER
(A
DDRESS
= 0
X
01) ......................................................................................... 300
T
ABLE
61: 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
................................................................... 300
Figure 133. Waveform/Timing Relationship between RxLineClk, RxPOS and RxNEG - When RxPOS and
RxNEG are to be sampled on the rising edge of RxLineClk ................................................................ 301
Figure 134. Waveform/Timing Relationship between RxLineClk, RxPOS and RxNEG - When RxPOS and
RxNEG are to be sampled on the falling edge of RxLineClk ............................................................... 301
5.3.2 The Receive E3 Framer Block ............................................................................................................... 301
Figure 135. A Simple Illustration of the Receive E3 Framer Block and the Associated Paths to the Other
Functional Blocks ................................................................................................................................ 302
Figure 136. The State Machine Diagram for the Receive E3 Framer E3 Frame Acquisition/Maintenance Al-
gorithm ................................................................................................................................................. 303
Figure 137. Illustration of the E3, ITU-T G.751 Framing Format ........................................................ 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) ....................................................... 305
R
X
E3 I
NTERRUPT
S
TATUS
R
EGISTER
- 1 (A
DDRESS
= 0
X
14) .................................................................. 305
R
X
E3 I
NTERRUPT
S
TATUS
R
EGISTER
- 1 (A
DDRESS
= 0
X
14) .................................................................. 305
R
X
E3 C
ONFIGURATION
& S
TATUS
R
EGISTER
- 2 (A
DDRESS
= 0
X
11) ....................................................... 306
PMON F
RAMING
B
IT
/B
YTE
E
RROR
C
OUNT
R
EGISTER
- MSB (A
DDRESS
= 0
X
52) ................................... 306
PMON F
RAMING
B
IT
/B
YTE
E
RROR
C
OUNT
R
EGISTER
- LSB (A
DDRESS
= 0
X
53) .................................... 306
R
X
E3 C
ONFIGURATION
& S
TATUS
R
EGISTER
- 2 (A
DDRESS
= 0
X
11) ....................................................... 307
T
ABLE
62: 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
............................................................................ 307
R
X
E3 C
ONFIGURATION
& S
TATUS
R
EGISTER
- 2 (A
DDRESS
= 0
X
11) ....................................................... 308
R
X
E3 I
NTERRUPT
S
TATUS
R
EGISTER
- 1 (A
DDRESS
= 0
X
14) .................................................................. 308
R
X
E3 C
ONFIGURATION
& S
TATUS
R
EGISTER
- 2 (A
DDRESS
= 0
X
11) ....................................................... 308
R
X
E3 I
NTERRUPT
S
TATUS
R
EGISTER
- 1 (A
DDRESS
= 0
X
14) .................................................................. 309