XRT72L56
SIX CHANNEL DS3/E3 FRAMER IC WITH HDLC CONTROLLER
REV. P1.1.2
á
PRELIMINARY
XVIII
R
X
E3 LAPD C
ONTROL
R
EGISTER
(A
DDRESS
= 0
X
18) ............................................................................ 428
R
X
E3 LAPD S
TATUS
R
EGISTER
(A
DDRESS
= 0
X
19) .............................................................................. 428
Figure 201. Flow Chart depicting the Functionality of the LAPD Receiver ......................................... 429
Figure 202. Flow Chart depicting the Functionality of the LAPD Receiver (Continued) ..................... 430
6.3.4 The Receive Overhead Data Output Interface ...................................................................................... 430
Figure 203. A Simple Illustration of the Receive Overhead Output Interface block ............................ 430
Figure 204. Illustration of how to interface the Terminal Equipment to the Receive Overhead Data Output
Interface block (for Method 1). ............................................................................................................. 431
T
ABLE
88: L
ISTING
AND
D
ESCRIPTION
OF
THE
P
IN
A
SSOCIATED
WITH
THE
R
ECEIVE
O
VERHEAD
D
ATA
O
UTPUT
I
NTERFACE
B
LOCK
................................................................................................................................. 432
T
ABLE
89: T
HE
R
ELATIONSHIP
BETWEEN
THE
N
UMBER
OF
R
ISING
C
LOCK
E
DGES
IN
R
X
OHC
LK
, (
SINCE
R
X
O-
HF
RAME
WAS
LAST
SAMPLED
"H
IGH
")
TO
THE
E3 O
VERHEAD
B
IT
,
THAT
IS
BEING
OUTPUT
VIA
THE
R
X
OH
OUTPUT
PIN
........................................................................................................................................................ 432
Figure 205. Illustration of the signals that are output via the Receive Overhead Output Interface (for Method
1). ........................................................................................................................................................ 434
T
ABLE
90: L
ISTING
AND
D
ESCRIPTION
OF
THE
P
IN
A
SSOCIATED
WITH
THE
R
ECEIVE
O
VERHEAD
D
ATA
O
UTPUT
I
NTERFACE
B
LOCK
(M
ETHOD
2) ............................................................................................................. 435
Figure 206. Illustration of how to interface the Terminal Equipment to the Receive Overhead Data Output
Interface block (for Method 2). ............................................................................................................. 436
T
ABLE
91: T
HE
R
ELATIONSHIP
BETWEEN
THE
N
UMBER
OF
R
X
OHE
NABLE
OUTPUT
PULSES
(
SINCE
R
X
OHF
RAME
WAS
LAST
SAMPLED
"H
IGH
")
TO
THE
E3 O
VERHEAD
B
IT
,
THAT
IS
BEING
OUTPUT
VIA
THE
R
X
OH
OUTPUT
PIN
...
436
Figure 207. Illustration of the signals that are output via the Receive Overhead Data Output Interface block
(for Method 2). ..................................................................................................................................... 439
6.3.5 The Receive Payload Data Output Interface ......................................................................................... 439
Figure 208. A Simple illustration of the Receive Payload Data Output Interface block ...................... 440
T
ABLE
92: L
ISTING
AND
D
ESCRIPTION
OF
THE
PIN
ASSOCIATED
WITH
THE
R
ECEIVE
P
AYLOAD
D
ATA
O
UTPUT
I
N
-
TERFACE
BLOCK
.................................................................................................................................... 441
Figure 209. Illustration of the Receive Payload Data Output Interface Block (of the XRT72L56 DS3/E3
Framer IC) being interfaced to the Receive Terminal Equipment (Serial Mode Operation) ................ 442
Figure 210. An Illustration of the behavior of the signals between the Receive Payload Data Output Inter-
face block of the XRT72L56 and the Terminal Equipment .................................................................. 443
Figure 211. Illustration of the XRT72L56 DS3/E3 Framer IC being interfaced to the Receive Section of the
Terminal Equipment (Nibble-Mode Operation) .................................................................................... 444
Figure 212. Illustration of the signals that are output via the Receive Overhead Data Output Interface block
(for Method 2). ..................................................................................................................................... 445
6.3.6 Receive Section Interrupt Processing ................................................................................................... 445
B
LOCK
I
NTERRUPT
E
NABLE
R
EGISTER
(A
DDRESS
= 0
X
04) ...................................................................... 446
R
X
E3 I
NTERRUPT
E
NABLE
R
EGISTER
- 1 (A
DDRESS
= 0
X
12) .................................................................. 446
R
X
E3 I
NTERRUPT
S
TATUS
R
EGISTER
- 1 (A
DDRESS
= 0
X
14) .................................................................. 447
R
X
E3 C
ONFIGURATION
& S
TATUS
R
EGISTER
2 (A
DDRESS
= 0
X
11) ......................................................... 447
R
X
E3 I
NTERRUPT
E
NABLE
R
EGISTER
- 1 (A
DDRESS
= 0
X
12) .................................................................. 448
R
X
E3 I
NTERRUPT
S
TATUS
R
EGISTER
- 1 (A
DDRESS
= 0
X
14) .................................................................. 448
R
X
E3 C
ONFIGURATION
& S
TATUS
R
EGISTER
2 (A
DDRESS
= 0
X
11) ......................................................... 448
R
X
E3 I
NTERRUPT
E
NABLE
R
EGISTER
- 1 (A
DDRESS
= 0
X
12) .................................................................. 449
R
X
E3 C
ONFIGURATION
& S
TATUS
R
EGISTER
2 (A
DDRESS
= 0
X
11) ......................................................... 449
R
X
E3 I
NTERRUPT
ENABLE R
EGISTER
- 1 (A
DDRESS
= 0
X
12) ................................................................ 450
R
X
E3 I
NTERRUPT
S
TATUS
R
EGISTER
- 1 (A
DDRESS
= 0
X
14) .................................................................. 450
R
X
E3 I
NTERRUPT
E
NABLE
R
EGISTER
- 1 (A
DDRESS
= 0
X
12) .................................................................. 450
R
X
E3 I
NTERRUPT
S
TATUS
R
EGISTER
- 1 (A
DDRESS
= 0
X
14) .................................................................. 451
R
X
E3 C
ONFIGURATION
& S
TATUS
R
EGISTER
2 (A
DDRESS
= 0
X
11) ......................................................... 451
R
X
E3 I
NTERRUPT
E
NABLE
R
EGISTER
- 2 (A
DDRESS
= 0
X
13) .................................................................. 451
R
X
E3 I
NTERRUPT
S
TATUS
R
EGISTER
- 2 (A
DDRESS
= 0
X
15) .................................................................. 452
R
X
E3 I
NTERRUPT
E
NABLE
R
EGISTER
- 2 (A
DDRESS
= 0
X
13) .................................................................. 452
R
X
E3 I
NTERRUPT
S
TATUS
R
EGISTER
- 2 (A
DDRESS
= 0
X
15) .................................................................. 453