
XRT74L74
4 CHANNEL, ATM UNI/PPP DS3/E3 FRAMING CONTROLLER
PRELIMINARY
B
LOCK
I
NTERRUPT
E
NABLE
R
EGISTER
(A
DDRESS
= 0
X
04).......................................................................................... 242
T
RANSMIT
DS3 FEAC C
ONFIGURATION
& S
TATUS
R
EGISTER
(A
DDRESS
= 0
X
31)....................................................... 242
T
RANSMIT
DS3 FEAC C
ONFIGURATION
& S
TATUS
R
EGISTER
(A
DDRESS
= 0
X
31)....................................................... 243
T
X
DS3 LAPD S
TATUS
AND
I
NTERRUPT
R
EGISTER
(A
DDRESS
= 0
X
34) .......................................................................243
T
X
DS3 LAPD S
TATUS
AND
I
NTERRUPT
R
EGISTER
(A
DDRESS
= 0
X
34) .......................................................................244
5.3 THE RECEIVE SECTION OF THE XRT74L74 (DS3 MODE OPERATION) ................................................ 244
F
IGURE
79. A S
IMPLE
I
LLUSTRATION
OF
THE
R
ECEIVE
S
ECTION
OF
THE
XRT74L74,
WHEN
IT
HAS
BEEN
CONFIGURED
TO
OPERATE
IN
THE
DS3
M
ODE
................................................................................................................................................................................. 244
5.3.1 THE RECEIVE DS3 LIU INTERFACE BLOCK......................................................................................................... 244
F
IGURE
80. A S
IMPLE
I
LLUSTRATION
OF
THE
R
ECEIVE
DS3 LIU I
NTERFACE
B
LOCK
............................................................................. 245
F
IGURE
81. B
EHAVIOR
OF
THE
R
X
POS, R
X
NEG
AND
R
X
L
INE
C
LK
SIGNALS
DURING
DATA
RECEPTION
OF
U
NIPOLAR
D
ATA
.................... 245
I/O C
ONTROL
R
EGISTER
(A
DDRESS
= 0
X
01)..............................................................................................................246
T
ABLE
51: T
HE
R
ELATIONSHIP
BETWEEN
THE
CONTENTS
OF
B
IT
3 (U
NIPOLAR
/B
IPOLAR
)
WITHIN
THE
I/O C
ONTROL
R
EGISTER
AND
THE
T
X
L
I
-
NE
C
LK
CLOCK
EDGE
THAT
T
X
POS
AND
T
X
NEG
ARE
UPDATED
ON
........................................................................................ 246
F
IGURE
82. I
LLUSTRATION
ON
HOW
THE
R
ECEIVE
DS3 F
RAMER
(
WITHIN
THE
XRT74L74 F
RAMER
IC)
BEING
INTERFACED
TO
THE
XRT73L00
LIU,
WHILE
THE
F
RAMER
IS
OPERATING
IN
B
IPOLAR
M
ODE
(
ONE
CHANNEL
SHOWN
)............................................................... 246
F
IGURE
83. I
LLUSTRATION
OF
AMI L
INE
C
ODE
.................................................................................................................................... 247
F
IGURE
84. I
LLUSTRATION
OF
TWO
EXAMPLES
OF
B3ZS D
ECODING
..................................................................................................... 248
II/O C
ONTROL
R
EGISTER
(A
DDRESS
= 0
X
01)............................................................................................................. 248
T
ABLE
52: 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
SAMPLING
EDGE
OF
THE
R
X
L
INE
C
LK
SIGNAL
................................................................................................................................................. 249
F
IGURE
85. W
AVEFORM
/T
IMING
R
ELATIONSHIP
BETWEEN
R
X
L
INE
C
LK
, R
X
POS
AND
R
X
NEG - W
HEN
R
X
POS
AND
R
X
NEG
ARE
TO
BE
SAMPLED
ON
THE
RISING
EDGE
OF
R
X
L
INE
C
LK
................................................................................................................................... 249
F
IGURE
86. W
AVEFORM
/T
IMING
R
ELATIONSHIP
BETWEEN
R
X
L
INE
C
LK
, R
X
POS
AND
R
X
NEG - W
HEN
R
X
POS
AND
R
X
NEG
ARE
TO
BE
SAMPLED
ON
THE
FALLING
EDGE
OF
R
X
L
INE
C
LK
................................................................................................................................. 249
5.3.2 THE RECEIVE DS3 FRAMER BLOCK..................................................................................................................... 250
F
IGURE
87. A S
IMPLE
I
LLUSTRATION
OF
THE
R
ECEIVE
DS3 F
RAMER
B
LOCK
AND
THE
A
SSOCIATED
P
ATHS
TO
THE
O
THER
F
UNCTIONAL
B
LOCKS
250
F
IGURE
88. T
HE
S
TATE
M
ACHINE
D
IAGRAM
FOR
THE
R
ECEIVE
DS3 F
RAMER
BLOCK
’
S
F
RAME
A
CQUISITION
/M
AINTENANCE
A
LGORITHM
251
R
X
DS3 C
ONFIGURATION
AND
S
TATUS
R
EGISTER
, (A
DDRESS
= 0
X
10) .......................................................................252
T
ABLE
53: T
HE
R
ELATIONSHIP
BETWEEN
THE
CONTENTS
OF
B
IT
2 (F
RAMING
ON
P
ARITY
)
WITHIN
THE
R
X
DS3 C
ONFIGURATION
AND
S
TATUS
R
EGISTER
,
AND
THE
RESULTING
F
RAMING
A
CQUISITION
C
RITERIA
......................................................................................... 252
R
X
DS3 C
ONFIGURATION
AND
S
TATUS
R
EGISTER
, (A
DDRESS
= 0
X
10) .......................................................................252
T
ABLE
54: T
HE
R
ELATIONSHIP
BETWEEN
THE
CONTENTS
OF
B
IT
1 (F-S
YNC
A
LGO
)
WITHIN
THE
R
X
DS3 C
ONFIGURATION
AND
S
TATUS
R
EGISTER
,
AND
THE
RESULTING
F-
BIT
OOF D
ECLARATION
CRITERIA
USED
BY
THE
R
ECEIVE
DS3 F
RAMER
BLOCK
................................... 253
R
X
DS3 C
ONFIGURATION
AND
S
TATUS
R
EGISTER
, (A
DDRESS
= 0
X
10) .......................................................................253
T
ABLE
55: T
HE
R
ELATIONSHIP
BETWEEN
THE
CONTENTS
OF
B
IT
0 (M-S
YNC
A
LGO
)
WITHIN
THE
R
X
DS3 C
ONFIGURATION
AND
S
TATUS
R
EGIS
-
TER
,
AND
THE
RESULTING
M-B
IT
OOF D
ECLARATION
C
RITERIA
USED
BY
THE
R
ECEIVE
DS3 F
RAMER
BLOCK
......................... 253
R
X
DS3 C
ONFIGURATION
AND
S
TATUS
R
EGISTER
, (A
DDRESS
= 0
X
10) .......................................................................253
I/O C
ONTROL
R
EGISTER
(A
DDRESS
= 0
X
01)..............................................................................................................254
PMON F
RAMING
B
IT
E
RROR
E
VENT
C
OUNT
R
EGISTER
- MSB (A
DDRESS
= 0
X
52) ..................................................... 254
PMON F
RAMING
B
IT
E
RROR
E
VENT
C
OUNT
R
EGISTER
- LSB (A
DDRESS
= 0
X
53) ......................................................254
R
X
DS3 C
ONFIGURATION
AND
S
TATUS
R
EGISTER
, (A
DDRESS
= 0
X
10) .......................................................................255
R
X
DS3 C
ONFIGURATION
AND
S
TATUS
R
EGISTER
, (A
DDRESS
= 0
X
10) .......................................................................255
R
X
DS3 C
ONFIGURATION
AND
S
TATUS
R
EGISTER
, (A
DDRESS
= 0
X
10) .......................................................................256
R
X
DS3 C
ONFIGURATION
AND
S
TATUS
R
EGISTER
, (A
DDRESS
= 0
X
10) .......................................................................256
R
X
DS3 C
ONFIGURATION
AND
S
TATUS
R
EGISTER
, (A
DDRESS
= 0
X
10) .......................................................................256
R
X
DS3 S
TATUS
R
EGISTER
(A
DDRESS
= 0
X
11).........................................................................................................257
R
X
DS3 I
NTERRUPT
S
TATUS
R
EGISTER
(A
DDRESS
= 0
X
13) ....................................................................................... 257
R
X
DS3 S
TATUS
R
EGISTER
(A
DDRESS
= 0
X
11).......................................................................................................... 258
R
X
DS3 I
NTERRUPT
S
TATUS
R
EGISTER
(A
DDRESS
= 0
X
13) ........................................................................................258
PMON P
ARITY
E
RROR
E
VENT
C
OUNT
R
EGISTER
- MSB (A
DDRESS
= 0
X
54).............................................................. 258
PMON P
ARITY
E
RROR
E
VENT
C
OUNT
R
EGISTER
- LSB (A
DDRESS
= 0
X
55)............................................................... 258
F
IGURE
89. A S
IMPLE
I
LLUSTRATION
OF
THE
L
OCATIONS
OF
THE
S
OURCE
, M
ID
-N
ETWORK
AND
S
INK
T
ERMINAL
E
QUIPMENT
(
FOR
CP-B
IT
P
RO
-
CESSING
)............................................................................................................................................................................ 259
F
IGURE
90. I
LLUSTRATION
OF
THE
P
RESUMED
C
ONFIGURATION
OF
THE
M
ID
-N
ETWORK
T
ERMINAL
E
QUIPMENT
..................................... 260
5.3.3 THE RECEIVE HDLC CONTROLLER BLOCK ........................................................................................................ 261
R
X
DS3 FEAC I
NTERRUPT
E
NABLE
/S
TATUS
R
EGISTER
(A
DDRESS
= 0
X
17)................................................................ 262
R
X
DS3 FEAC R
EGISTER
(A
DDRESS
= 0
X
16) ........................................................................................................... 262
R
X
DS3 FEAC I
NTERRUPT
E
NABLE
/S
TATUS
R
EGISTER
(A
DDRESS
= 0
X
17)................................................................ 262
F
IGURE
91. F
LOW
D
IAGRAM
DEPICTING
HOW
THE
R
ECEIVE
FEAC P
ROCESSOR
F
UNCTIONS
................................................................. 263
F
IGURE
92. LAPD M
ESSAGE
F
RAME
F
ORMAT
..................................................................................................................................... 264
REV. P1.1.1
V