xr
TWO CHANNEL DS3/E3 FRAMER IC WITH HDLC CONTROLLER
XRT72L52
REV. 1.0.1
VII
I/O C
ONTROL
R
EGISTER
(A
DDRESS
= 0
X
01)............................................................................................197
PMON F
RAMING
B
IT
E
RROR
E
VENT
C
OUNT
R
EGISTER
- MSB (A
DDRESS
= 0
X
52)...................................197
PMON F
RAMING
B
IT
E
RROR
E
VENT
C
OUNT
R
EGISTER
- LSB (A
DDRESS
= 0
X
53)....................................198
R
X
DS3 C
ONFIGURATION
AND
S
TATUS
R
EGISTER
, (A
DDRESS
= 0
X
10).....................................................198
F
RAMER
O
PERATING
M
ODE
R
EGISTER
(A
DDRESS
= 0
X
00).......................................................................199
R
X
DS3 C
ONFIGURATION
AND
S
TATUS
R
EGISTER
, (A
DDRESS
= 0
X
10).....................................................199
R
X
DS3 C
ONFIGURATION
AND
S
TATUS
R
EGISTER
, (A
DDRESS
= 0
X
10).....................................................200
R
X
DS3 S
TATUS
R
EGISTER
(A
DDRESS
= 0
X
11).......................................................................................201
R
X
DS3 I
NTERRUPT
S
TATUS
R
EGISTER
(A
DDRESS
= 0
X
13).....................................................................201
R
X
DS3 S
TATUS
R
EGISTER
(A
DDRESS
= 0
X
11)........................................................................................202
R
X
DS3 I
NTERRUPT
S
TATUS
R
EGISTER
(A
DDRESS
= 0
X
13)......................................................................202
PMON P
ARITY
E
RROR
E
VENT
C
OUNT
R
EGISTER
- MSB (A
DDRESS
= 0
X
54)............................................203
PMON P
ARITY
E
RROR
E
VENT
C
OUNT
R
EGISTER
- LSB (A
DDRESS
= 0
X
55).............................................203
Figure 70. A Simple Illustration of the Locations of the Source, Mid-Network and Sink Terminal Equipment (for CP-Bit
Processing).................................................................................................................................................... 204
Figure 71. Illustration of the Presumed Configuration of the Mid-Network Terminal Equipment .................................. 205
4.3.3 The Receive HDLC Controller Block.................................................................................................... 205
R
X
DS3 FEAC I
NTERRUPT
E
NABLE
/S
TATUS
R
EGISTER
(A
DDRESS
= 0
X
17)..............................................207
R
X
DS3 FEAC R
EGISTER
(A
DDRESS
= 0
X
16).........................................................................................207
R
X
DS3 FEAC I
NTERRUPT
E
NABLE
/S
TATUS
R
EGISTER
(A
DDRESS
= 0
X
17)..............................................207
Figure 72. Flow Diagram depicting how the Receive FEAC Processor Functions....................................................... 208
Figure 73. LAPD Message Frame Format.................................................................................................................... 209
R
X
DS3 LAPD C
ONTROL
R
EGISTER
(A
DDRESS
= 0
X
18)..........................................................................210
R
X
DS3 LAPD S
TATUS
R
EGISTER
(A
DDRESS
= 0
X
19) ............................................................................210
T
ABLE
37: T
HE
R
ELATIONSHIP
BETWEEN
R
X
LAPDT
YPE
[1:0]
AND
THE
RESULTING
LAPD M
ESSAGE
TYPE
AND
SIZE
........... 210
Figure 74. Flow Chart depicting the Functionality of the LAPD Receiver..................................................................... 212
4.3.4 The Receive Overhead Data Output Interface..................................................................................... 212
Figure 75. The Receive Overhead Output Interface block ........................................................................................... 213
T
ABLE
38: 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
214
Figure 76. The Terminal Equipment being interfaced to the Receive Overhead Data Output Interface Block (Method 1)214
T
ABLE
39: T
HE
R
ELATIONSHIP
BETWEEN
THE
N
UMBER
OF
R
ISING
C
LOCK
E
DGES
IN
R
X
OHC
LK
, (
SINCE
R
X
OHF
RAME
WAS
LAST
SAMPLED
"H
IGH
")
TO
THE
DS3 O
VERHEAD
B
IT
,
THAT
IS
BEING
OUTPUT
VIA
THE
R
X
OH
OUTPUT
PIN
................... 215
Figure 77. Illustration of the signals that are output via the Receive Overhead Output Interface (for Method 1)......... 217
T
ABLE
40: 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).................................................................................................................................................... 217
Figure 78. The Terminal Equipment being interfaced to the Receive Overhead Data Output Interface (Method 2) .... 218
T
ABLE
41: 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
DS3 O
VERHEAD
B
IT
,
THAT
IS
BEING
OUTPUT
VIA
THE
R
X
OH
OUTPUT
PIN
................... 219
Figure 79. Illustration of the signals that are output via the Receive Overhead Data Output Interface block (for Method 2).
221
4.3.5 The Receive Payload Data Output Interface........................................................................................ 221
Figure 80. The Receive Payload Data Output Interface block...................................................................................... 221
T
ABLE
42: L
ISTING
AND
D
ESCRIPTION
OF
THE
PIN
ASSOCIATED
WITH
THE
R
ECEIVE
P
AYLOAD
D
ATA
O
UTPUT
I
NTERFACE
BLOCK
222
Figure 81. The XRT72L52 DS3/E3 Framer IC being interfaced to the Receive Terminal Equipment (Serial Mode Operation)
224
Figure 82. An Illustration of the behavior of the signals between the Receive Payload Data Output Interface block of the
XRT72L52 and the Terminal Equipment (Serial Mode Operation) ................................................................ 225
Figure 83. The XRT72L52 DS3/E3 Framer IC being interfaced to the Receive Section of the Terminal Equipment (Nibble-
Parallel Mode Operation)............................................................................................................................... 226
Figure 84. An Illustration of the Behavior of the signals between the Receive Payload Data Output Interface Block of the
XRT72L52 and the Terminal Equipment (Nibble-Mode Operation)............................................................... 227
4.3.6 Receive Section Interrupt Processing.................................................................................................. 227
B
LOCK
I
NTERRUPT
E
NABLE
R
EGISTER
(A
DDRESS
= 0
X
04) .......................................................................228
R
X
DS3 I
NTERRUPT
E
NABLE
R
EGISTER
(A
DDRESS
= 0
X
12)......................................................................228
R
X
DS3 I
NTERRUPT
S
TATUS
R
EGISTER
(A
DDRESS
= 0
X
13)......................................................................229
R
X
DS3 C
ONFIGURATION
& S
TATUS
R
EGISTER
(A
DDRESS
= 0
X
10)...........................................................229
R
X
DS3 I
NTERRUPT
E
NABLE
R
EGISTER
(A
DDRESS
= 0
X
12)......................................................................230
R
X
DS3 I
NTERRUPT
S
TATUS
R
EGISTER
(A
DDRESS
= 0
X
13)......................................................................230
R
X
DS3 C
ONFIGURATION
& S
TATUS
R
EGISTER
(A
DDRESS
= 0
X
10)...........................................................230