XRT72L52
TWO CHANNEL DS3/E3 FRAMER IC WITH HDLC CONTROLLER
REV. P1.1.3
á
PRELIMINARY
VI
face block of the XRT72L52 for Mode 2 (Serial/Local-Timed/Frame-Slave) Operation ...................... 151
Figure 47. Behavior of the Terminal Interface signals between the XRT72L52 and the Terminal Equipment
(Mode 2 Operation) ............................................................................................................................. 152
F
RAMER
O
PERATING
M
ODE
R
EGISTER
(A
DDRESS
= 0
X
00) ..................................................................... 152
Figure 48. Illustration of the Terminal Equipment being interfaced to the Transmit Payload Data Input Inter-
face block of the XRT72L52 for Mode 3 (Serial/Local-Timed/Frame-Master) Operation .................... 153
Figure 49. Behavior of the Terminal Interface signals between the XRT72L52 and the Terminal Equipment
(DS3 Mode 3 Operation) ..................................................................................................................... 154
F
RAMER
O
PERATING
M
ODE
R
EGISTER
(A
DDRESS
= 0
X
00) ..................................................................... 155
Figure 50. Illustration of the Terminal Equipment being interfaced to the Transmit Payload Data Input Inter-
face block of the XRT72L52 for Mode 4 (Nibble-Parallel/Loop-Timed) Operation .............................. 156
Figure 51. Behavior of the Terminal Interface signals between the XRT72L52 and the Terminal Equipment
(Mode 4 Operation) ............................................................................................................................. 157
F
RAMER
O
PERATING
M
ODE
R
EGISTER
(A
DDRESS
= 0
X
00) ..................................................................... 157
Figure 52. Illustration of the Terminal Equipment being interfaced to the Transmit Payload Data Input Inter-
face block of the XRT72L52 for Mode 5 (Nibble-Parallel/Local-Timed/Frame-Slave) Operation ........ 159
Figure 53. Behavior of the Terminal Interface signals between the XRT72L52 and the Terminal Equipment
(DS3 Mode 5 Operation) ..................................................................................................................... 160
F
RAMER
O
PERATING
M
ODE
R
EGISTER
(A
DDRESS
= 0
X
00) ..................................................................... 160
Figure 54. Illustration of the Terminal Equipment being interfaced to the Transmit Payload Data Input Inter-
face block of the XRT72L52 for Mode 6 (Nibble-Parallel/Local-Timed/Frame-Master) Operation ...... 161
Figure 55. Behavior of the Terminal Interface signals between the XRT72L52 and the Terminal Equipment
(DS3 Mode 6 Operation) ..................................................................................................................... 162
F
RAMER
O
PERATING
M
ODE
R
EGISTER
(A
DDRESS
= 0
X
00) ..................................................................... 163
4.2.2 The Transmit Overhead Data Input Interface ........................................................................................ 163
Figure 56. Simple Illustration of the Transmit Overhead Data Input Interface block .......................... 163
T
ABLE
20: A L
ISTING
OF
THE
O
VERHEAD
BITS
WITHIN
THE
DS3
FRAME
,
AND
THEIR
POTENTIAL
SOURCES
,
WITHIN
THE
XRT72L52 IC ................................................................................................................................ 164
T
ABLE
21: D
ESCRIPTION
OF
M
ETHOD
1 T
RANSMIT
O
VERHEAD
I
NPUT
I
NTERFACE
S
IGNALS
...................... 165
Figure 57. Illustration of the Terminal Equipment being interfaced to the Transmit Overhead Data Input In-
terface (Method 1) ............................................................................................................................... 166
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
............... 167
Figure 58. 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 .... 169
T
ABLE
23: D
ESCRIPTION
OF
M
ETHOD
2 T
RANSMIT
O
VERHEAD
I
NPUT
I
NTERFACE
S
IGNALS
...................... 170
Figure 59. Illustration of the Terminal Equipment being interfaced to the Transmit Overhead Data Input In-
terface (Method 2) ............................................................................................................................... 171
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
XRT72L52 172
Figure 60. Behavior of Transmit Overhead Data Input Interface signals between the XRT72L52 and the
Terminal Equipment (for Method 2) ..................................................................................................... 174
4.2.3 The Transmit DS3 HDLC Controller ...................................................................................................... 174
T
X
DS3 FEAC R
EGISTER
(A
DDRESS
= 0
X
32) ........................................................................................ 175
T
RANSMIT
DS3 FEAC C
ONFIGURATION
AND
S
TATUS
R
EGISTER
(A
DDRESS
= 0
X
31) ............................... 175
T
RANSMIT
DS3 FEAC C
ONFIGURATION
AND
S
TATUS
R
EGISTER
(A
DDRESS
= 0
X
31) ............................... 175
Figure 61. A Flow Chart depicting how to transmit a FEAC Message via the FEAC Transmitter ...... 176
Figure 62. LAPD Message Frame Format .......................................................................................... 177
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
.................................................................................................................................. 177
T
RANSMIT
DS3 LAPD C
ONFIGURATION
R
EGISTER
(A
DDRESS
= 0
X
33) ................................................... 178
T
ABLE
26: R
ELATIONSHIP
BETWEEN
T
X
LAPD M
SG
L
ENGTH
AND
THE
LAPD M
ESSAGE
S
IZE
.................. 178
T
RANSMIT
DS3 LAPD C
ONFIGURATION
R
EGISTER
(A
DDRESS
= 0
X
33) ................................................... 178
T
ABLE
27: R
ELATIONSHIP
BETWEEN
T
X
LAPD M
SG
L
ENGTH
AND
THE
LAPD M
ESSAGE
S
IZE
.................. 178
T
RANSMIT
DS3 LAPD S
TATUS
/I
NTERRUPT
R
EGISTER
(A
DDRESS
= 0
X
34) ............................................... 179