
DS2156
4 of 262
17.
18.
CHANNEL BLOCKING REGISTERS ..................................................................................................107
ELASTIC STORES OPERATION..........................................................................................................110
R
ECEIVE
S
IDE
..........................................................................................................................................113
18.1.1
T1 Mode..............................................................................................................................................113
18.1.2
E1 Mode..............................................................................................................................................113
18.2
T
RANSMIT
S
IDE
.......................................................................................................................................113
18.2.1
T1 Mode..............................................................................................................................................114
18.2.2
E1 Mode..............................................................................................................................................114
18.3
E
LASTIC
S
TORES
I
NITIALIZATION
...........................................................................................................114
T
ABLE
18-A. E
LASTIC
S
TORE
D
ELAY
A
FTER
I
NITIALIZATION
.............................................................................114
18.4
M
INIMUM
D
ELAY
M
ODE
.........................................................................................................................114
18.1
19.
G.706 INTERMEDIATE CRC-4 UPDATING (E1 MODE ONLY).....................................................115
F
IGURE
19-1. CRC-4 R
ECALCULATE
M
ETHOD
....................................................................................................115
20.
T1 BIT-ORIENTED CODE (BOC) CONTROLLER............................................................................116
T
RANSMIT
BOC.......................................................................................................................................116
Transmit a BOC ................................................................................................................................................116
20.2
R
ECEIVE
BOC .........................................................................................................................................116
Receive a BOC ..................................................................................................................................................116
20.1
21.
ADDITIONAL (SA) AND INTERNATIONAL (SI) BIT OPERATION (E1 ONLY) ........................119
M
ETHOD
1: H
ARDWARE
S
CHEME
...........................................................................................................119
M
ETHOD
2: I
NTERNAL
R
EGISTER
S
CHEME
B
ASED ON
D
OUBLE
-F
RAME
................................................119
M
ETHOD
3: I
NTERNAL
R
EGISTER
S
CHEME
B
ASED ON
CRC4 M
ULTIFRAME
..........................................122
21.1
21.2
21.3
22.
HDLC CONTROLLERS..........................................................................................................................132
B
ASIC
O
PERATION
D
ETAILS
....................................................................................................................132
HDLC C
ONFIGURATION
..........................................................................................................................132
T
ABLE
22-A. HDLC C
ONTROLLER
R
EGISTERS
....................................................................................................133
22.2.1
FIFO Control......................................................................................................................................136
22.3
HDLC M
APPING
......................................................................................................................................137
22.3.1
Receive................................................................................................................................................137
22.3.2
Transmit..............................................................................................................................................139
22.3.3
FIFO Information...............................................................................................................................144
22.3.4
Receive Packet-Bytes Available..........................................................................................................144
22.3.5
HDLC FIFOs......................................................................................................................................145
22.4
R
ECEIVE
HDLC C
ODE
E
XAMPLE
............................................................................................................146
22.5
L
EGACY
FDL S
UPPORT
(T1 M
ODE
)........................................................................................................146
22.5.1
Overview.............................................................................................................................................146
22.5.2
Receive Section...................................................................................................................................146
22.5.3
Transmit Section.................................................................................................................................148
22.6
D4/SLC-96 O
PERATION
..........................................................................................................................148
22.1
22.2
23.
LINE INTERFACE UNIT (LIU).............................................................................................................149
LIU O
PERATION
......................................................................................................................................149
R
ECEIVER
................................................................................................................................................149
23.2.1
Receive Level Indicator and Threshold Interrupt...............................................................................150
23.2.2
Receive G.703 Synchronization Signal (E1 Mode).............................................................................150
23.2.3
Monitor Mode.....................................................................................................................................150
F
IGURE
23-1. T
YPICAL
M
ONITOR
A
PPLICATION
...................................................................................................150
23.3
T
RANSMITTER
.........................................................................................................................................151
23.3.1
Transmit Short-Circuit Detector/Limiter............................................................................................151
23.1
23.2