XRT74L74
4 CHANNEL, ATM UNI/PPP DS3/E3 FRAMING CONTROLLER
PRELIMINARY
6.1 DESCRIPTION OF THE E3, ITU-T G.751 FRAMES AND ASSOCIATED OVERHEAD BITS .................... 295
F
IGURE
104. T
HE
E3, ITU-T G.751 F
RAMING
F
ORMAT
....................................................................................................................... 295
6.1.1 DEFINITION OF THE OVERHEAD BITS.................................................................................................................. 295
6.2 THE TRANSMIT SECTION OF THE XRT74L74 (E3, ITU-T G.751 MODE OPERATION) .......................... 296
F
IGURE
105. T
HE
XRT74L74 T
RANSMIT
S
ECTION
WHEN
IT
HAS
BEEN
CONFIGURED
TO
OPERATE
IN
THE
E3 M
ODE
............................... 296
6.2.1 THE TRANSMIT PAYLOAD DATA INPUT INTERFACE BLOCK ........................................................................... 296
F
IGURE
106. T
HE
T
RANSMIT
P
AYLOAD
D
ATA
I
NPUT
I
NTERFACE
B
LOCK
................................................................................................ 297
T
ABLE
62: L
ISTING
AND
D
ESCRIPTION
OF
THE
PINS
ASSOCIATED
WITH
THE
T
RANSMIT
P
AYLOAD
D
ATA
I
NPUT
I
NTERFACE
....................... 298
F
IGURE
107. 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
1 (S
ERIAL
/L
OOP
-T
IMED
) O
PERATION
.................................................................................................................. 300
T
X
E3 C
ONFIGURATION
R
EGISTER
(A
DDRESS
= 0
X
30) ................................................................................................ 301
F
IGURE
108. B
EHAVIOR
OF
THE
T
ERMINAL
I
NTERFACE
SIGNALS
BETWEEN
THE
XRT74L74 T
RANSMIT
P
AYLOAD
D
ATA
I
NPUT
I
NTERFACE
BLOCK
AND
THE
T
ERMINAL
E
QUIPMENT
(
FOR
M
ODE
1 O
PERATION
) ................................................................................................. 302
F
RAMER
O
PERATING
M
ODE
R
EGISTER
(A
DDRESS
= 0
X
00)......................................................................................... 302
F
IGURE
109. 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
2 (S
ERIAL
/L
OCAL
-T
IMED
/F
RAME
-S
LAVE
) O
PERATION
.......................................................................................... 303
F
IGURE
110. B
EHAVIOR
OF
THE
T
ERMINAL
I
NTERFACE
SIGNALS
BETWEEN
THE
XRT74L74
AND
THE
T
ERMINAL
E
QUIPMENT
(M
ODE
2 O
PERATION
)
304
F
RAMER
O
PERATING
M
ODE
R
EGISTER
(A
DDRESS
= 0
X
00)......................................................................................... 304
F
IGURE
111. 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
3 (S
ERIAL
/L
OCAL
-T
IME
/F
RAME
-M
ASTER
) O
PERATION
......................................................................................... 305
F
IGURE
112. B
EHAVIOR
OF
THE
T
ERMINAL
I
NTERFACE
SIGNALS
BETWEEN
THE
XRT74L74
AND
THE
T
ERMINAL
E
QUIPMENT
(E3 M
ODE
3 O
PER
-
ATION
)................................................................................................................................................................................ 306
F
RAMER
O
PERATING
M
ODE
R
EGISTER
(A
DDRESS
= 0
X
00)......................................................................................... 306
F
IGURE
113. 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
.................................................................................................. 307
F
IGURE
114. B
EHAVIOR
OF
THE
T
ERMINAL
I
NTERFACE
SIGNALS
BETWEEN
THE
XRT74L74
AND
THE
T
ERMINAL
E
QUIPMENT
(M
ODE
4 O
PERATION
)
308
F
RAMER
O
PERATING
M
ODE
R
EGISTER
(A
DDRESS
= 0
X
00)......................................................................................... 308
F
IGURE
115. 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
IMED
/F
RAME
-S
LAVE
) O
PERATION
.......................................................................... 309
F
IGURE
116. 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
)................................................................................................................................................................................ 310
F
RAMER
O
PERATING
M
ODE
R
EGISTER
(A
DDRESS
= 0
X
00)......................................................................................... 310
F
IGURE
117. 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 (N
IBBLE
-P
ARALLEL
/L
OCAL
-T
IMED
/F
RAME
-M
ASTER
) O
PERATION
....................................................................... 311
F
IGURE
118. 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
)................................................................................................................................................................................ 312
F
RAMER
O
PERATING
M
ODE
R
EGISTER
(A
DDRESS
= 0
X
00)......................................................................................... 312
6.2.2 THE TRANSMIT OVERHEAD DATA INPUT INTERFACE ...................................................................................... 313
F
IGURE
119. T
HE
T
RANSMIT
O
VERHEAD
D
ATA
I
NPUT
I
NTERFACE
BLOCK
.............................................................................................. 313
T
ABLE
63: A L
ISTING
OF
THE
O
VERHEAD
BITS
WITHIN
THE
E3
FRAME
,
AND
THEIR
POTENTIAL
SOURCES
................................................ 314
T
ABLE
64: D
ESCRIPTION
OF
M
ETHOD
1 T
RANSMIT
O
VERHEAD
I
NPUT
I
NTERFACE
S
IGNALS
................................................................... 315
F
IGURE
120. T
HE
T
ERMINAL
E
QUIPMENT
BEING
INTERFACED
TO
THE
T
RANSMIT
O
VERHEAD
D
ATA
I
NPUT
I
NTERFACE
(M
ETHOD
1) ......... 316
T
ABLE
65: 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
........................................................................................................ 317
F
IGURE
121. 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
........................................... 318
T
ABLE
66: D
ESCRIPTION
OF
M
ETHOD
2 T
RANSMIT
O
VERHEAD
I
NPUT
I
NTERFACE
S
IGNALS
................................................................... 319
F
IGURE
122. T
HE
T
ERMINAL
E
QUIPMENT
BEING
INTERFACED
TO
THE
T
RANSMIT
O
VERHEAD
D
ATA
I
NPUT
I
NTERFACE
(M
ETHOD
2) ......... 320
T
ABLE
67: 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 .......................................................................... 321
F
IGURE
123. 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)................................................................................................................................................................. 322
6.2.3 THE TRANSMIT E3 HDLC CONTROLLER.............................................................................................................. 322
F
IGURE
124. LAPD M
ESSAGE
F
RAME
F
ORMAT
................................................................................................................................... 323
T
ABLE
68: T
HE
LAPD M
ESSAGE
T
YPE
AND
THE
C
ORRESPONDING
VALUE
OF
THE
F
IRST
B
YTE
,
WITHIN
THE
I
NFORMATION
P
AYLOAD
...... 324
T
X
E3 C
ONFIGURATION
R
EGISTER
(A
DDRESS
= 0
X
30) ................................................................................................ 324
T
RANSMIT
E3 LAPD C
ONFIGURATION
R
EGISTER
(A
DDRESS
= 0
X
33).......................................................................... 325
T
ABLE
69: R
ELATIONSHIP
BETWEEN
T
X
LAPD M
SG
L
ENGTH
AND
THE
LAPD M
ESSAGE
S
IZE
................................................................ 325
T
X
E3 LAPD C
ONFIGURATION
R
EGISTER
(A
DDRESS
= 0
X
33)...................................................................................... 325
T
RANSMIT
E3 LAPD C
ONFIGURATION
R
EGISTER
(A
DDRESS
= 0
X
33).......................................................................... 326
T
X
E3 LAPD S
TATUS
AND
I
NTERRUPT
R
EGISTER
(A
DDRESS
= 0
X
34).......................................................................... 326
T
X
E3 LAPD S
TATUS
AND
I
NTERRUPT
R
EGISTER
(A
DDRESS
= 0
X
34).......................................................................... 327
REV. P1.1.1
VII