xr
TWO CHANNEL DS3/E3 FRAMER IC WITH HDLC CONTROLLER
XRT72L52
REV. 1.0.1
XIII
Figure 160. The Terminal Equipment being interfaced to the Transmit Overhead Data Input Interface (Method 2)..... 374
T
ABLE
72: T
HE
R
ELATIONSHIP
BETWEEN
THE
N
UMBER
OF
T
X
OHE
NABLE
PULSES
(
SINCE
THE
LAST
OCCURRENCE
OF
THE
T
X
OHF
RAME
PULSE
)
TO
THE
E3 O
VERHEAD
B
IT
,
THAT
IS
BEING
PROCESSED
BY
THE
XRT72L52...................... 374
Figure 161. Behavior of Transmit Overhead Data Input Interface signals between the XRT72L52 and the Terminal
Equipment (for Method 2).............................................................................................................................. 377
6.2.3 The Transmit E3 HDLC Controller ....................................................................................................... 377
Figure 162. LAPD Message Frame Format.................................................................................................................. 378
T
ABLE
73: T
HE
LAPD M
ESSAGE
T
YPE
AND
THE
C
ORRESPONDING
VALUE
OF
THE
F
IRST
B
YTE
,
WITHIN
THE
I
NFORMATION
P
AYLOAD
379
T
RANSMIT
E3 LAPD C
ONFIGURATION
R
EGISTER
(A
DDRESS
= 0
X
33) .......................................................380
T
ABLE
74: R
ELATIONSHIP
BETWEEN
T
X
LAPD M
SG
L
ENGTH
AND
THE
LAPD M
ESSAGE
S
IZE
............................................. 380
T
X
E3 C
ONFIGURATION
R
EGISTER
(A
DDRESS
= 0
X
30)..............................................................................380
T
X
E3 LAPD C
ONFIGURATION
R
EGISTER
(A
DDRESS
= 0
X
33) ...................................................................381
T
RANSMIT
E3 LAPD C
ONFIGURATION
R
EGISTER
(A
DDRESS
= 0
X
33) .......................................................381
T
X
E3 LAPD S
TATUS
AND
I
NTERRUPT
R
EGISTER
(A
DDRESS
= 0
X
34)........................................................382
T
X
E3 LAPD S
TATUS
AND
I
NTERRUPT
R
EGISTER
(A
DDRESS
= 0
X
34)........................................................382
Figure 163. Flow Chart depicting how to use the LAPD Transmitter (LAPD Transmitter is configured to re-transmit the LAPD
Message frame repeatedly at One-Second intervals) ................................................................................... 384
Figure 164. Flow Chart depicting how to use the LAPD Transmitter (LAPD Transmitter is configured to transmit a LAPD
Message frame only once). ........................................................................................................................... 385
B
LOCK
I
NTERRUPT
E
NABLE
R
EGISTER
(A
DDRESS
= 0
X
04) .......................................................................386
6.2.4 The Transmit E3 Framer Block ............................................................................................................ 386
Figure 165. The Transmit E3 Framer Block and the associated paths to other Functional Blocks............................... 387
T
X
E3 C
ONFIGURATION
R
EGISTER
(A
DDRESS
= 0
X
30)..............................................................................388
T
ABLE
75: T
HE
R
ELATIONSHIP
BETWEEN
THE
CONTENTS
OF
B
IT
2 (T
X
AIS E
NABLE
)
WITHIN
THE
T
X
E3 C
ONFIGURATION
R
EGISTER
,
AND
THE
RESULTING
T
RANSMIT
E3 F
RAMER
B
LOCK
'
S
A
CTION
........................................................................... 388
T
ABLE
76: T
HE
R
ELATIONSHIP
BETWEEN
THE
CONTENTS
OF
B
IT
1 (T
X
LOS)
WITHIN
THE
T
X
E3 C
ONFIGURATION
R
EGISTER
,
AND
THE
RESULTING
T
RANSMIT
E3 F
RAMER
B
LOCK
'
S
A
CTION
.................................................................................. 389
6.2.5 The Transmit E3 Line Interface Block.................................................................................................. 390
Figure 166. Interfacing the XRT72L52 Framer IC to the XRT73L00 DS3/E3/STS-1 LIU............................................. 391
Figure 167. The Transmit E3 LIU Interface block ......................................................................................................... 392
Figure 168. The Behavior of TxPOS and TxNEG signals during data transmission while the Transmit E3 LIU Interface is
operating in the Unipolar Mode ..................................................................................................................... 392
I/O C
ONTROL
R
EGISTER
(A
DDRESS
= 0
X
01)............................................................................................393
T
ABLE
77: T
HE
R
ELATIONSHIP
BETWEEN
THE
CONTENT
OF
B
IT
3 (U
NIPOLAR
/B
IPOLAR
)
WITHIN
THE
UNI I/O C
ONTROL
R
EGISTER
AND
THE
T
RANSMIT
E3 F
RAMER
L
INE
I
NTERFACE
O
UTPUT
M
ODE
...................................................................... 393
Figure 169. Illustration of AMI Line Code ..................................................................................................................... 394
Figure 170. Illustration of two examples of HDB3 Encoding......................................................................................... 394
I/O C
ONTROL
R
EGISTER
(A
DDRESS
= 0
X
01)............................................................................................395
T
ABLE
78: T
HE
R
ELATIONSHIP
BETWEEN
B
IT
4 (AMI/HDB3*)
WITHIN
THE
I/O C
ONTROL
R
EGISTER
AND
THE
B
IPOLAR
L
INE
C
ODE
THAT
IS
OUTPUT
BY
THE
T
RANSMIT
E3 LIU I
NTERFACE
B
LOCK
.......................................................................... 395
T
ABLE
79: 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
............................................................. 395
Figure 171. Waveform/Timing Relationship between TxLineClk, TxPOS and TxNEG - TxPOS and TxNEG are configured to
be updated on the rising edge of TxLineClk.................................................................................................. 396
Figure 172. Waveform/Timing Relationship between TxLineClk, TxPOS and TxNEG - TxPOS and TxNEG are configured to
be updated on the falling edge of TxLineClk ................................................................................................. 396
6.2.6 Transmit Section Interrupt Processing................................................................................................. 396
B
LOCK
I
NTERRUPT
E
NABLE
R
EGISTER
(A
DDRESS
= 0
X
04) .......................................................................397
T
X
E3 LAPD S
TATUS
AND
I
NTERRUPT
R
EGISTER
(A
DDRESS
= 0
X
34)........................................................397
T
X
E3 LAPD S
TATUS
AND
I
NTERRUPT
R
EGISTER
(A
DDRESS
= 0
X
34)........................................................398
6.3 T
HE
R
ECEIVE
S
ECTION
OF
THE
XRT72L52 (E3 M
ODE
O
PERATION
) ................................................................. 398
Figure 173. The XRT72L52 Receive Section configured to operate in the E3 Mode................................................... 399
6.3.1 The Receive E3 LIU Interface Block .................................................................................................... 399
Figure 174. The Receive E3 LIU Interface Block.......................................................................................................... 399
Figure 175. Behavior of the RxPOS, RxNEG and RxLineClk signals during data reception of Unipolar Data............. 400
I/O C
ONTROL
R
EGISTER
(A
DDRESS
= 0
X
01)............................................................................................400
T
ABLE
80: T
HE
R
ELATIONSHIP
BETWEEN
THE
CONTENTS
OF
B
IT
3 (U
NIPOLAR
/B
IPOLAR
)
WITHIN
THE
I/O C
ONTROL
R
EGISTER
400
Figure 176. Interfacing the XRT72L52 Framer IC to the XRT73L00 DS3/E3/STS-1 LIU............................................. 401
Figure 177. Illustration of AMI Line Code ..................................................................................................................... 402
Figure 178. Illustration of two examples of HDB3 Decoding ........................................................................................ 402
I/O C
ONTROL
R
EGISTER
(A
DDRESS
= 0
X
01)............................................................................................403
T
ABLE
81: 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
EGISTER
,
AND
THE