
xr
TWO CHANNEL DS3/E3 FRAMER IC WITH HDLC CONTROLLER
XRT72L52
REV. 1.0.1
V
Operation)...................................................................................................................................................... 142
F
RAMER
O
PERATING
M
ODE
R
EGISTER
(A
DDRESS
= 0
X
00).......................................................................142
Figure 38. The Terminal Equipment being interfaced to the Transmit Payload Data Input Interface block for Mode 4 (Nibble-
Parallel/Loop-Timed) Operation .................................................................................................................... 143
Figure 39. Behavior of the Terminal Interface signals between the XRT72L52 and the Terminal Equipment (Mode 4
Operation)...................................................................................................................................................... 144
F
RAMER
O
PERATING
M
ODE
R
EGISTER
(A
DDRESS
= 0
X
00).......................................................................145
Figure 40. The Terminal Equipment being interfaced to the Transmit Payload Data Input Interface block for Mode 5 (Nibble-
Parallel/Local-Timed/Frame-Slave) Operation .............................................................................................. 146
Figure 41. Behavior of the Terminal Interface signals between the XRT72L52 and the Terminal Equipment (DS3 Mode 5
Operation)...................................................................................................................................................... 147
F
RAMER
O
PERATING
M
ODE
R
EGISTER
(A
DDRESS
= 0
X
00).......................................................................147
Figure 42. The Terminal Equipment being interfaced to the Transmit Payload Data Input Interface block for Mode 6 (Nibble-
Parallel/Local-Timed/Frame-Master) Operation ............................................................................................ 148
Figure 43. Behavior of the Terminal Interface signals between the XRT72L52 and the Terminal Equipment (DS3 Mode 6
Operation)...................................................................................................................................................... 149
F
RAMER
O
PERATING
M
ODE
R
EGISTER
(A
DDRESS
= 0
X
00).......................................................................150
4.2.2 The Transmit Overhead Data Input Interface....................................................................................... 151
Figure 44. The Transmit Overhead Data Input Interface block..................................................................................... 151
T
ABLE
16: O
VERHEAD
BITS
WITHIN
THE
DS3
FRAME
AND
THEIR
POTENTIAL
SOURCES
WITHIN
THE
XRT72L52 IC............... 152
T
ABLE
17: D
ESCRIPTION
OF
M
ETHOD
1 T
RANSMIT
O
VERHEAD
I
NPUT
I
NTERFACE
S
IGNALS
................................................ 153
Figure 45. The Terminal Equipment being interfaced to the Transmit Overhead Data Input Interface (Method 1)....... 154
T
ABLE
18: 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
DS3 O
VERHEAD
B
IT
THAT
IS
BEING
PROCESSED
......................................................... 154
Figure 46. Illustration of the signal that must occur between the Terminal Equipment and the XRT72L52, in order to configure
the XRT72L52 to transmit a Yellow Alarm to the remote terminal equipment............................................... 157
T
ABLE
19: D
ESCRIPTION
OF
M
ETHOD
2 T
RANSMIT
O
VERHEAD
I
NPUT
I
NTERFACE
S
IGNALS
................................................ 158
Figure 47. The Terminal Equipment being interfaced to the Transmit Overhead Data Input Interface (Method 2)....... 159
T
ABLE
20: 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
DS3 O
VERHEAD
B
IT
THAT
IS
BEING
PROCESSED
BY
THE
XRT72L52..................... 159
Figure 48. Behavior of Transmit Overhead Data Input Interface signals between the XRT72L52 and the Terminal Equipment
(for Method 2)................................................................................................................................................ 162
4.2.3 The Transmit DS3 HDLC Controller..................................................................................................... 162
T
X
DS3 FEAC R
EGISTER
(A
DDRESS
= 0
X
32) .........................................................................................164
T
RANSMIT
DS3 FEAC C
ONFIGURATION
AND
S
TATUS
R
EGISTER
(A
DDRESS
= 0
X
31).................................164
T
RANSMIT
DS3 FEAC C
ONFIGURATION
AND
S
TATUS
R
EGISTER
(A
DDRESS
= 0
X
31).................................164
Figure 49. A Flow Chart depicting how to transmit a FEAC Message via the FEAC Transmitter................................. 165
Figure 50. LAPD Message Frame Format.................................................................................................................... 166
T
ABLE
21: T
HE
LAPD M
ESSAGE
T
YPE
AND
THE
C
ORRESPONDING
VALUE
OF
THE
F
IRST
B
YTE
WITHIN
THE
I
NFORMATION
P
AYLOAD
167
T
RANSMIT
DS3 LAPD C
ONFIGURATION
R
EGISTER
(A
DDRESS
= 0
X
33).....................................................167
T
ABLE
22: R
ELATIONSHIP
BETWEEN
T
X
LAPD M
SG
L
ENGTH
AND
THE
LAPD M
ESSAGE
S
IZE
............................................. 167
T
RANSMIT
DS3 LAPD C
ONFIGURATION
R
EGISTER
(A
DDRESS
= 0
X
33).....................................................168
T
ABLE
23: R
ELATIONSHIP
BETWEEN
T
X
LAPD M
SG
L
ENGTH
AND
THE
LAPD M
ESSAGE
S
IZE
............................................. 168
T
RANSMIT
DS3 LAPD S
TATUS
/I
NTERRUPT
R
EGISTER
(A
DDRESS
= 0
X
34)................................................168
Figure 51. Flow Chart depict how to use the LAPD Transmitter................................................................................... 170
F
RAMER
O
PERATING
M
ODE
R
EGISTER
(A
DDRESS
= 0
X
00).......................................................................171
B
LOCK
I
NTERRUPT
E
NABLE
R
EGISTER
(A
DDRESS
= 0
X
04) .......................................................................171
4.2.4 The Transmit DS3 Framer Block.......................................................................................................... 171
Figure 52. The Transmit DS3 Framer Block and the associated paths to other Functional Blocks.............................. 173
T
X
DS3 C
ONFIGURATION
R
EGISTER
(A
DDRESS
= 0
X
30) ..........................................................................173
T
ABLE
24: T
HE
R
ELATIONSHIP
BETWEEN
THE
CONTENTS
OF
B
IT
7 (T
X
Y
ELLOW
A
LARM
)
WITHIN
THE
T
X
DS3 C
ONFIGURATION
R
EGISTER
,
AND
THE
RESULTING
T
RANSMIT
DS3 F
RAMER
B
LOCK
'
S
A
CTION
........................................................ 174
T
ABLE
25: T
HE
R
ELATIONSHIP
BETWEEN
THE
CONTENTS
OF
B
IT
6 (T
X
X-B
ITS
)
WITHIN
THE
T
X
DS3 C
ONFIGURATION
R
EGISTER
,
AND
THE
RESULTING
T
RANSMIT
DS3 F
RAMER
B
LOCK
'
S
A
CTION
................................................................................ 174
T
ABLE
26: T
HE
R
ELATIONSHIP
BETWEEN
THE
CONTENTS
OF
B
IT
5 (T
X
I
DLE
)
WITHIN
THE
T
X
DS3 C
ONFIGURATION
R
EGISTER
,
AND
THE
RESULTING
T
RANSMIT
DS3 F
RAMER
A
CTION
.............................................................................................. 175
T
ABLE
27: T
HE
R
ELATIONSHIP
BETWEEN
THE
CONTENTS
OF
B
IT
4 (T
X
AIS P
ATTERN
)
WITHIN
THE
T
X
DS3 C
ONFIGURATION
R
EGISTER
,
AND
THE
RESULTING
T
RANSMIT
DS3 F
RAMER
B
LOCK
'
S
A
CTION
........................................................ 175
T
ABLE
28: T
HE
R
ELATIONSHIP
BETWEEN
THE
CONTENTS
OF
B
IT
3 (T
X
LOS)
WITHIN
THE
T
X
DS3 C
ONFIGURATION
R
EGISTER
,
AND
THE
RESULTING
T
RANSMIT
DS3 F
RAMER
B
LOCK
'
S
A
CTION
................................................................................ 176
T
X
DS3 M-B
IT
M
ASK
R
EGISTER
, A
DDRESS
= 0
X
35 .................................................................................177
T
X
DS3 F-B
IT
M
ASK
1 R
EGISTER
, A
DDRESS
= 0
X
36 ................................................................................177