
XRT72L53
THREE CHANNEL DS3/E3 FRAMER IC WITH HDLC CONTROLLER
REV. P1.1.6
á
PRELIMINARY
VI
Figure 47. Behavior of the Terminal Interface signals between the XRT72L53 and the Terminal Equipment
(Mode 2 Operation) ............................................................................................................................. 160
F
RAMER
O
PERATING
M
ODE
R
EGISTER
(A
DDRESS
= 0
X
00) ..................................................................... 160
Figure 48. Illustration of the Terminal Equipment being interfaced to the Transmit Payload Data Input Inter-
face block of the XRT72L53 for Mode 3 (Serial/Local-Timed/Frame-Master) Operation .................... 161
Figure 49. Behavior of the Terminal Interface signals between the XRT72L53 and the Terminal Equipment
(DS3 Mode 3 Operation) ..................................................................................................................... 162
F
RAMER
O
PERATING
M
ODE
R
EGISTER
(A
DDRESS
= 0
X
00) ..................................................................... 163
Figure 50. Illustration of the Terminal Equipment being interfaced to the Transmit Payload Data Input Inter-
face block of the XRT72L53 for Mode 4 (Nibble-Parallel/Loop-Timed) Operation .............................. 164
Figure 51. Behavior of the Terminal Interface signals between the XRT72L53 and the Terminal Equipment
(Mode 4 Operation) ............................................................................................................................. 165
F
RAMER
O
PERATING
M
ODE
R
EGISTER
(A
DDRESS
= 0
X
00) ..................................................................... 165
Figure 52. Illustration of the Terminal Equipment being interfaced to the Transmit Payload Data Input Inter-
face block of the XRT72L53 for Mode 5 (Nibble-Parallel/Local-Timed/Frame-Slave) Operation ........ 167
Figure 53. Behavior of the Terminal Interface signals between the XRT72L53 and the Terminal Equipment
(DS3 Mode 5 Operation) ..................................................................................................................... 168
F
RAMER
O
PERATING
M
ODE
R
EGISTER
(A
DDRESS
= 0
X
00) ..................................................................... 168
Figure 54. Illustration of the Terminal Equipment being interfaced to the Transmit Payload Data Input Inter-
face block of the XRT72L53 for Mode 6 (Nibble-Parallel/Local-Timed/Frame-Master) Operation ...... 169
Figure 55. Behavior of the Terminal Interface signals between the XRT72L53 and the Terminal Equipment
(DS3 Mode 6 Operation) ..................................................................................................................... 170
F
RAMER
O
PERATING
M
ODE
R
EGISTER
(A
DDRESS
= 0
X
00) ..................................................................... 171
4.2.2 The Transmit Overhead Data Input Interface ........................................................................................ 171
Figure 56. Simple Illustration of the Transmit Overhead Data Input Interface block .......................... 171
T
ABLE
20: A L
ISTING
OF
THE
O
VERHEAD
BITS
WITHIN
THE
DS3
FRAME
,
AND
THEIR
POTENTIAL
SOURCES
,
WITHIN
THE
XRT72L53 IC ................................................................................................................................ 172
T
ABLE
21: D
ESCRIPTION
OF
M
ETHOD
1 T
RANSMIT
O
VERHEAD
I
NPUT
I
NTERFACE
S
IGNALS
...................... 173
Figure 57. Illustration of the Terminal Equipment being interfaced to the Transmit Overhead Data Input In-
terface (Method 1) ............................................................................................................................... 174
T
ABLE
22: T
HE
R
ELATIONSHIP
BETWEEN
THE
N
UMBER
OF
R
ISING
C
LOCK
E
DGES
IN
T
X
OHC
LK
, (
SINCE
T
X
O-
HF
RAME
WAS
LAST
SAMPLED
"H
IGH
")
TO
THE
DS3 O
VERHEAD
B
IT
,
THAT
IS
BEING
PROCESSED
............... 175
Figure 58. Illustration of the signal that must occur between the Terminal Equipment and the XRT72L53,
in order to configure the XRT72L53 to transmit a Yellow Alarm to the remote terminal equipment .... 177
T
ABLE
23: D
ESCRIPTION
OF
M
ETHOD
2 T
RANSMIT
O
VERHEAD
I
NPUT
I
NTERFACE
S
IGNALS
...................... 178
Figure 59. Illustration of the Terminal Equipment being interfaced to the Transmit Overhead Data Input In-
terface (Method 2) ............................................................................................................................... 179
T
ABLE
24: 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
XRT72L53 180
Figure 60. Behavior of Transmit Overhead Data Input Interface signals between the XRT72L53 and the
Terminal Equipment (for Method 2) ..................................................................................................... 182
4.2.3 The Transmit DS3 HDLC Controller ...................................................................................................... 182
T
X
DS3 FEAC R
EGISTER
(A
DDRESS
= 0
X
32) ........................................................................................ 183
T
RANSMIT
DS3 FEAC C
ONFIGURATION
AND
S
TATUS
R
EGISTER
(A
DDRESS
= 0
X
31) ............................... 183
T
RANSMIT
DS3 FEAC C
ONFIGURATION
AND
S
TATUS
R
EGISTER
(A
DDRESS
= 0
X
31) ............................... 183
Figure 61. A Flow Chart depicting how to transmit a FEAC Message via the FEAC Transmitter ...... 184
Figure 62. LAPD Message Frame Format .......................................................................................... 185
T
ABLE
25: T
HE
LAPD M
ESSAGE
T
YPE
AND
THE
C
ORRESPONDING
VALUE
OF
THE
F
IRST
B
YTE
,
WITHIN
THE
I
NFOR
-
MATION
P
AYLOAD
.................................................................................................................................. 185
T
RANSMIT
DS3 LAPD C
ONFIGURATION
R
EGISTER
(A
DDRESS
= 0
X
33) ................................................... 186
T
ABLE
26: R
ELATIONSHIP
BETWEEN
T
X
LAPD M
SG
L
ENGTH
AND
THE
LAPD M
ESSAGE
S
IZE
.................. 186
T
RANSMIT
DS3 LAPD C
ONFIGURATION
R
EGISTER
(A
DDRESS
= 0
X
T
ABLE
27: R
ELATIONSHIP
BETWEEN
T
X
LAPD M
SG
L
ENGTH
AND
THE
LAPD M
ESSAGE
S
IZE
.................. 186
T
RANSMIT
DS3 LAPD S
TATUS
/I
NTERRUPT
R
EGISTER
(A
DDRESS
= 0
X
34) ............................................... 187
Figure 63. Flow Chart depict how to use the LAPD Transmitter ........................................................ 188