XRT74L74
4 CHANNEL, ATM UNI/PPP DS3/E3 FRAMING CONTROLLER
PRELIMINARY
REV. P1.1.1
XI
F
IGURE
170. T
HE
T
ERMINAL
E
QUIPMENT
BEING
INTERFACED
TO
THE
T
RANSMIT
P
AYLOAD
D
ATA
I
NPUT
I
NTERFACE
BLOCK
OF
THE
XRT74L74
FOR
M
ODE
4 (N
IBBLE
-P
ARALLEL
/L
OOP
-T
IMED
) O
PERATION
.................................................................................................. 402
F
IGURE
171. B
EHAVIOR
OF
THE
T
ERMINAL
I
NTERFACE
SIGNALS
BETWEEN
THE
XRT74L74
AND
THE
T
ERMINAL
E
QUIPMENT
(M
ODE
4 O
PERATION
)
403
F
RAMER
O
PERATING
M
ODE
R
EGISTER
(A
DDRESS
= 0
X
00)......................................................................................... 403
F
IGURE
172. T
HE
T
ERMINAL
E
QUIPMENT
BEING
INTERFACED
TO
THE
T
RANSMIT
P
AYLOAD
D
ATA
I
NPUT
I
NTERFACE
BLOCK
OF
THE
XRT74L74
FOR
M
ODE
5 (N
IBBLE
-P
ARALLEL
/L
OCAL
-T
IME
/F
RAME
-S
LAVE
) O
PERATION
............................................................................ 404
F
IGURE
173. B
EHAVIOR
OF
THE
T
ERMINAL
I
NTERFACE
SIGNALS
BETWEEN
THE
XRT74L74
AND
THE
T
ERMINAL
E
QUIPMENT
(E3 M
ODE
5 O
PER
-
ATION
)................................................................................................................................................................................ 405
F
RAMER
O
PERATING
M
ODE
R
EGISTER
(A
DDRESS
= 0
X
00)......................................................................................... 405
F
IGURE
174. T
HE
T
ERMINAL
E
QUIPMENT
BEING
INTERFACED
TO
THE
T
RANSMIT
P
AYLOAD
D
ATA
I
NPUT
I
NTERFACE
BLOCK
OF
THE
XRT74L74
FOR
M
ODE
6 O
PERATION
.................................................................................................................................................... 406
F
IGURE
175. B
EHAVIOR
OF
THE
T
ERMINAL
I
NTERFACE
SIGNALS
BETWEEN
THE
XRT74L74
AND
THE
T
ERMINAL
E
QUIPMENT
(E3 M
ODE
6 O
PER
-
ATION
)................................................................................................................................................................................ 407
F
RAMER
O
PERATING
M
ODE
R
EGISTER
(A
DDRESS
= 0
X
00)......................................................................................... 407
7.2.2 THE TRANSMIT OVERHEAD DATA INPUT INTERFACE ...................................................................................... 407
F
IGURE
176. T
HE
T
RANSMIT
O
VERHEAD
D
ATA
I
NPUT
I
NTERFACE
BLOCK
.............................................................................................. 408
T
ABLE
87: T
HE
O
VERHEAD
BITS
WITHIN
THE
E3
FRAME
AND
THEIR
POTENTIAL
SOURCES
...................................................................... 409
T
ABLE
88: D
ESCRIPTION
OF
M
ETHOD
1 T
RANSMIT
O
VERHEAD
I
NPUT
I
NTERFACE
S
IGNALS
................................................................... 411
F
IGURE
177. T
HE
T
ERMINAL
E
QUIPMENT
BEING
INTERFACED
TO
THE
T
RANSMIT
O
VERHEAD
D
ATA
I
NPUT
I
NTERFACE
(M
ETHOD
1) ......... 412
T
ABLE
89: T
HE
R
ELATIONSHIP
BETWEEN
THE
N
UMBER
OF
R
ISING
C
LOCK
E
DGES
IN
T
X
OHC
LK
, (
SINCE
"T
X
OHF
RAME
"
WAS
LAST
SAMPLED
"H
IGH
")
TO
THE
E3 O
VERHEAD
B
IT
,
THAT
IS
BEING
PROCESSED
............................................................................................ 413
F
IGURE
178. I
LLUSTRATION
OF
THE
SIGNAL
THAT
MUST
OCCUR
BETWEEN
THE
T
ERMINAL
E
QUIPMENT
AND
THE
XRT74L74,
IN
ORDER
TO
CON
-
FIGURE
THE
XRT74L74
TO
TRANSMIT
A
Y
ELLOW
A
LARM
TO
THE
REMOTE
TERMINAL
EQUIPMENT
........................................... 415
T
ABLE
90: D
ESCRIPTION
OF
M
ETHOD
1 T
RANSMIT
O
VERHEAD
I
NPUT
I
NTERFACE
S
IGNALS
................................................................... 416
F
IGURE
179. T
HE
T
ERMINAL
E
QUIPMENT
BEING
INTERFACED
TO
THE
T
RANSMIT
O
VERHEAD
D
ATA
I
NPUT
I
NTERFACE
(M
ETHOD
2) ......... 417
T
ABLE
91: 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
XRT74L74 .......................................................................... 418
F
IGURE
180. B
EHAVIOR
OF
T
RANSMIT
O
VERHEAD
D
ATA
I
NPUT
I
NTERFACE
SIGNALS
BETWEEN
THE
XRT74L74
AND
THE
T
ERMINAL
E
QUIPMENT
FOR
M
ETHOD
2................................................................................................................................................................... 420
7.2.3 THE TRANSMIT E3 HDLC CONTROLLER.............................................................................................................. 420
F
IGURE
181. LAPD M
ESSAGE
F
RAME
F
ORMAT
................................................................................................................................... 421
T
ABLE
92: T
HE
LAPD M
ESSAGE
T
YPE
AND
THE
C
ORRESPONDING
VALUE
OF
THE
F
IRST
B
YTE
,
WITHIN
THE
I
NFORMATION
P
AYLOAD
...... 422
T
RANSMIT
E3 LAPD C
ONFIGURATION
R
EGISTER
(A
DDRESS
= 0
X
33).......................................................................... 422
T
ABLE
93: R
ELATIONSHIP
BETWEEN
T
X
LAPD M
SG
L
ENGTH
AND
THE
LAPD M
ESSAGE
S
IZE
................................................................ 423
T
X
E3 C
ONFIGURATION
R
EGISTER
(A
DDRESS
= 0
X
30) ................................................................................................ 423
T
X
E3 LAPD C
ONFIGURATION
R
EGISTER
(A
DDRESS
= 0
X
33)...................................................................................... 423
T
RANSMIT
E3 LAPD C
ONFIGURATION
R
EGISTER
(A
DDRESS
= 0
X
33).......................................................................... 424
T
X
E3 LAPD S
TATUS
AND
I
NTERRUPT
R
EGISTER
(A
DDRESS
= 0
X
34).......................................................................... 424
T
X
E3 LAPD S
TATUS
AND
I
NTERRUPT
R
EGISTER
(A
DDRESS
= 0
X
34).......................................................................... 425
F
IGURE
182. F
LOW
C
HART
DEPICTING
HOW
TO
USE
THE
LAPD T
RANSMITTER
(LAPD T
RANSMITTER
IS
CONFIGURED
TO
RE
-
TRANSMIT
THE
LAPD
M
ESSAGE
FRAME
REPEATEDLY
AT
O
NE
-S
ECOND
INTERVALS
) ............................................................................................... 426
F
IGURE
183. F
LOW
C
HART
DEPICTING
HOW
TO
USE
THE
LAPD T
RANSMITTER
(LAPD T
RANSMITTER
IS
CONFIGURED
TO
TRANSMIT
A
LAPD M
ES
-
SAGE
FRAME
ONLY
ONCE
).................................................................................................................................................... 427
B
LOCK
I
NTERRUPT
E
NABLE
R
EGISTER
(A
DDRESS
= 0
X
04).......................................................................................... 428
7.2.4 THE TRANSMIT E3 FRAMER BLOCK..................................................................................................................... 428
F
IGURE
184. T
HE
T
RANSMIT
E3 F
RAMER
B
LOCK
AND
THE
ASSOCIATED
PATHS
TO
OTHER
F
UNCTIONAL
B
LOCKS
................................... 429
T
X
E3 C
ONFIGURATION
R
EGISTER
(A
DDRESS
= 0
X
30) ................................................................................................ 430
T
ABLE
94: 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
............................................................................................................ 430
T
ABLE
95: 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
.............................................................................................................................. 430
7.2.5 THE TRANSMIT E3 LINE INTERFACE BLOCK ...................................................................................................... 431
F
IGURE
185. A
PPROACH
TO
I
NTERFACING
THE
XRT74L74 F
RAMER
IC
TO
THE
XRT73L00 DS3/E3/STS-1 LIU .................................. 432
F
IGURE
186. T
HE
T
RANSMIT
E3 LIU I
NTERFACE
BLOCK
...................................................................................................................... 433
F
IGURE
187. T
HE
B
EHAVIOR
OF
T
X
POS
AND
T
X
NEG
SIGNALS
DURING
DATA
TRANSMISSION
WHILE
THE
T
RANSMIT
DS3 LIU I
NTERFACE
IS
OP
-
ERATING
IN
THE
U
NIPOLAR
M
ODE
........................................................................................................................................ 433
I/O C
ONTROL
R
EGISTER
(A
DDRESS
= 0
X
01)..............................................................................................................434
T
ABLE
96: 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
....................................................................................................... 434
F
IGURE
188. AMI L
INE
C
ODE
............................................................................................................................................................. 435
F
IGURE
189. T
WO
EXAMPLES
OF
HDB3 E
NCODING
............................................................................................................................. 435
I/O C
ONTROL
R
EGISTER
(A
DDRESS
= 0
X
01)..............................................................................................................436
T
ABLE
97: 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