
XRT74L74
4 CHANNEL, ATM UNI/PPP DS3/E3 FRAMING CONTROLLER
PRELIMINARY
REV. P1.1.1
XIII
THE
MA
BYTE
-
FIELD
SET
TO
“1”........................................................................................................................................... 458
R
X
E3 I
NTERRUPT
S
TATUS
R
EGISTER
- 2 (A
DDRESS
= 0
X
15)...................................................................................... 458
PMON P
ARITY
E
RROR
C
OUNT
R
EGISTER
- MSB (A
DDRESS
= 0
X
54)......................................................................... 458
PMON P
ARITY
E
RROR
C
OUNT
R
EGISTER
- LSB (A
DDRESS
= 0
X
55).......................................................................... 459
R
X
E3 I
NTERRUPT
S
TATUS
R
EGISTER
- 2 (A
DDRESS
= 0
X
15)...................................................................................... 459
PMON FEBE E
VENT
C
OUNT
R
EGISTER
- MSB (A
DDRESS
= 0
X
56) ........................................................................... 459
PMON FEBE E
VENT
C
OUNT
R
EGISTER
- LSB (A
DDRESS
= 0
X
57) ............................................................................ 459
R
X
E3 I
NTERRUPT
S
TATUS
R
EGISTER
- 2 (A
DDRESS
= 0
X
15)...................................................................................... 460
7.3.3 THE RECEIVE HDLC CONTROLLER BLOCK ........................................................................................................ 460
F
IGURE
207. LAPD M
ESSAGE
F
RAME
F
ORMAT
................................................................................................................................... 461
R
X
E3 LAPD C
ONTROL
R
EGISTER
(A
DDRESS
= 0
X
18)................................................................................................ 462
R
X
E3 LAPD C
ONTROL
R
EGISTER
(A
DDRESS
= 0
X
18)................................................................................................ 462
R
X
E3 LAPD S
TATUS
R
EGISTER
(A
DDRESS
= 0
X
19) .................................................................................................. 462
R
X
E3 LAPD S
TATUS
R
EGISTER
(A
DDRESS
= 0
X
19) .................................................................................................. 463
R
X
E3 LAPD S
TATUS
R
EGISTER
(A
DDRESS
= 0
X
19) .................................................................................................. 463
R
X
E3 LAPD S
TATUS
R
EGISTER
(A
DDRESS
= 0
X
19) .................................................................................................. 464
R
X
E3 LAPD S
TATUS
R
EGISTER
(A
DDRESS
= 0
X
19) .................................................................................................. 464
T
ABLE
102: T
HE
R
ELATIONSHIP
BETWEEN
THE
C
ONTENTS
OF
R
X
LAPDT
YPE
[1:0]
BIT
-
FIELDS
AND
THE
PMDL M
ESSAGE
T
YPE
/S
IZE
..... 464
R
X
E3 LAPD C
ONTROL
R
EGISTER
(A
DDRESS
= 0
X
18)................................................................................................ 465
R
X
E3 LAPD S
TATUS
R
EGISTER
(A
DDRESS
= 0
X
19) .................................................................................................. 465
F
IGURE
208. F
LOW
C
HART
DEPICTING
THE
F
UNCTIONALITY
OF
THE
LAPD R
ECEIVER
........................................................................... 466
F
IGURE
209. F
LOW
C
HART
DEPICTING
THE
F
UNCTIONALITY
OF
THE
LAPD R
ECEIVER
(C
ONTINUED
)...................................................... 467
7.3.4 THE RECEIVE OVERHEAD DATA OUTPUT INTERFACE ..................................................................................... 467
F
IGURE
210. T
HE
R
ECEIVE
O
VERHEAD
O
UTPUT
I
NTERFACE
BLOCK
..................................................................................................... 467
F
IGURE
211. H
OW
TO
INTERFACE
THE
T
ERMINAL
E
QUIPMENT
TO
THE
R
ECEIVE
O
VERHEAD
D
ATA
O
UTPUT
I
NTERFACE
BLOCK
FOR
M
ETHOD
1.
468
T
ABLE
103: L
ISTING
AND
D
ESCRIPTION
OF
THE
P
IN
A
SSOCIATED
WITH
THE
R
ECEIVE
O
VERHEAD
D
ATA
O
UTPUT
I
NTERFACE
B
LOCK
...... 469
T
ABLE
104: T
HE
R
ELATIONSHIP
BETWEEN
THE
N
UMBER
OF
R
ISING
C
LOCK
E
DGES
IN
R
X
OHC
LK
, (
SINCE
R
X
OHF
RAME
WAS
LAST
SAMPLED
"H
IGH
")
TO
THE
E3 O
VERHEAD
B
IT
,
THAT
IS
BEING
OUTPUT
VIA
THE
R
X
OH
OUTPUT
PIN
........................................................ 469
F
IGURE
212. T
HE
SIGNALS
THAT
ARE
OUTPUT
VIA
THE
R
ECEIVE
O
VERHEAD
O
UTPUT
I
NTERFACE
FOR
M
ETHOD
1.................................. 471
T
ABLE
105: L
ISTING
AND
D
ESCRIPTION
OF
THE
P
IN
A
SSOCIATED
WITH
THE
R
ECEIVE
O
VERHEAD
D
ATA
O
UTPUT
I
NTERFACE
B
LOCK
(M
ETHOD
2)
472
F
IGURE
213. H
OW
TO
INTERFACE
THE
T
ERMINAL
E
QUIPMENT
TO
THE
R
ECEIVE
O
VERHEAD
D
ATA
O
UTPUT
I
NTERFACE
BLOCK
FOR
M
ETHOD
2
473
T
ABLE
106: T
HE
R
ELATIONSHIP
BETWEEN
THE
N
UMBER
OF
R
X
OHE
NABLE
OUTPUT
PULSES
(
SINCE
R
X
OHF
RAME
WAS
LAST
SAMPLED
"H
IGH
")
TO
THE
E3 O
VERHEAD
B
IT
,
THAT
IS
BEING
OUTPUT
VIA
THE
R
X
OH
OUTPUT
PIN
.................................................................... 473
F
IGURE
214. T
HE
SIGNALS
THAT
ARE
OUTPUT
VIA
THE
R
ECEIVE
O
VERHEAD
D
ATA
O
UTPUT
I
NTERFACE
BLOCK
FOR
M
ETHOD
2.............. 476
7.3.5 THE RECEIVE PAYLOAD DATA OUTPUT INTERFACE........................................................................................ 476
F
IGURE
215. T
HE
R
ECEIVE
P
AYLOAD
D
ATA
O
UTPUT
I
NTERFACE
BLOCK
............................................................................................... 476
T
ABLE
107: L
ISTING
AND
D
ESCRIPTION
OF
THE
PIN
ASSOCIATED
WITH
THE
R
ECEIVE
P
AYLOAD
D
ATA
O
UTPUT
I
NTERFACE
BLOCK
........... 478
F
IGURE
216. T
HE
R
ECEIVE
P
AYLOAD
D
ATA
O
UTPUT
I
NTERFACE
B
LOCK
BEING
INTERFACED
TO
THE
R
ECEIVE
T
ERMINAL
E
QUIPMENT
(S
ERIAL
M
ODE
O
PERATION
)............................................................................................................................................................. 479
F
IGURE
217. T
HE
BEHAVIOR
OF
THE
SIGNALS
BETWEEN
THE
R
ECEIVE
P
AYLOAD
D
ATA
O
UTPUT
I
NTERFACE
BLOCK
OF
THE
XRT74L74
AND
THE
T
ERMINAL
E
QUIPMENT
........................................................................................................................................................ 480
F
IGURE
218. T
HE
XRT74L74 DS3/E3 F
RAMER
IC
BEING
INTERFACED
TO
THE
R
ECEIVE
S
ECTION
OF
THE
T
ERMINAL
E
QUIPMENT
(N
IBBLE
-M
ODE
O
PERATION
) ....................................................................................................................................................................... 481
F
IGURE
219. T
HE
SIGNALS
THAT
ARE
OUTPUT
VIA
THE
R
ECEIVE
O
VERHEAD
D
ATA
O
UTPUT
I
NTERFACE
BLOCK
FOR
M
ETHOD
2.............. 482
7.3.6 RECEIVE SECTION INTERRUPT PROCESSING.................................................................................................... 482
B
LOCK
I
NTERRUPT
E
NABLE
R
EGISTER
(A
DDRESS
= 0
X
04).......................................................................................... 483
R
X
E3 I
NTERRUPT
E
NABLE
R
EGISTER
- 1 (A
DDRESS
= 0
X
12)...................................................................................... 483
R
X
E3 I
NTERRUPT
S
TATUS
R
EGISTER
- 1 (A
DDRESS
= 0
X
14)...................................................................................... 484
R
X
E3 C
ONFIGURATION
& S
TATUS
R
EGISTER
2 (A
DDRESS
= 0
X
11)............................................................................. 484
R
X
E3 I
NTERRUPT
E
NABLE
R
EGISTER
- 1 (A
DDRESS
= 0
X
12)...................................................................................... 485
R
X
E3 I
NTERRUPT
S
TATUS
R
EGISTER
- 1 (A
DDRESS
= 0
X
14)...................................................................................... 485
R
X
E3 C
ONFIGURATION
& S
TATUS
R
EGISTER
2 (A
DDRESS
= 0
X
11)............................................................................. 485
R
X
E3 I
NTERRUPT
E
NABLE
R
EGISTER
- 1 (A
DDRESS
= 0
X
12)...................................................................................... 486
R
X
E3 C
ONFIGURATION
& S
TATUS
R
EGISTER
2 (A
DDRESS
= 0
X
11)............................................................................. 486
R
X
E3 I
NTERRUPT
ENABLE R
EGISTER
- 1 (A
DDRESS
= 0
X
12) ................................................................................... 487
R
X
E3 I
NTERRUPT
S
TATUS
R
EGISTER
- 1 (A
DDRESS
= 0
X
14)...................................................................................... 487
R
X
E3 I
NTERRUPT
E
NABLE
R
EGISTER
- 1 (A
DDRESS
= 0
X
12)...................................................................................... 487
R
X
E3 I
NTERRUPT
S
TATUS
R
EGISTER
- 1 (A
DDRESS
= 0
X
14)...................................................................................... 488
R
X
E3 C
ONFIGURATION
& S
TATUS
R
EGISTER
2 (A
DDRESS
= 0
X
11)............................................................................. 488