XRT72L56 Datasheet, PDF (433/486 Pages) Exar Corporation – SIX CHANNEL DS3/E3 FRAMER IC WITH HDLC CONTROLLER

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PRELIMINARY
XRT72L56
SIX CHANNEL DS3/E3 FRAMER IC WITH HDLC CONTROLLER
REV. P1.1.2
PMON FRAMING BIT/BYTE ERROR COUNT REGISTER - MSB (ADDRESS = 0X52)
BIT 7
BIT 6
BIT 5
BIT 4
BIT 3
BIT 2
BIT 1
Framing Bit/Byte Error Count - High Byte
RUR
RUR
RUR
RUR
RUR
RUR
RUR
0
0
0
0
0
0
0
BIT 0
RUR
0
PMON FRAMING BIT/BYTE ERROR COUNT REGISTER - LSB (ADDRESS = 0X53)
BIT 7
BIT 6
BIT 5
BIT 4
BIT 3
BIT 2
BIT 1
Framing Bit/Byte Error Count - Low Byte
RUR
RUR
RUR
RUR
RUR
RUR
RUR
0
0
0
0
0
0
0
BIT 0
RUR
0
6.3.2.3 Forcing a Reframe via Software Com-
mand
The XRT72L56 Framer IC permits the user to com-
mand a reframe procedure with the Receive E3 Fram-
er block via software command. If the user writes a
“1” into Bit 0 (Reframe) within the I/O Control Register
(Address = 0x01), as depicted below, then the Re-
ceive E3 Framer block will be forced into the FA1, FA2
Octet Search state, per Figure 194, and will begin its
search for the “FA1” and “FA2” octets.)
I/O CONTROL REGISTER (ADDRESS = 0X01)
BIT 7
BIT 6
BIT 5
BIT 4
BIT 3
BIT 2
BIT 1
BIT 0
Disable TxLOC LOC
Disable
RxLOC
AMI/ Unipolar/Bipo-
ZeroSup*
lar*
TxLine
Clk
Invert
RxLine
Clk
Invert
Reframe
R/W
RO
R/W
R/W
R/W
R/W
R/W
R/W
1
0
1
0
0
0
0
1
The Framer IC will respond to this command by doing
the following.
1. Asserting both the RxOOF and RxLOF output
pins.
2. Generating both the Change in OOF Status and
the Change in LOF Status interrupts to the Micro-
processor.
3. Asserting both the RxLOF and RxOOF bit-fields
within the Rx E3 Configuration & Status Register,
as depicted below.
RXE3 CONFIGURATION & STATUS REGISTER 2 (ADDRESS = 0X11)
BIT 7
BIT 6
BIT 5
BIT 4
BIT 3
BIT 2
BIT 1
BIT 0
Rx LOF Algo RxLOF
RxOOF
RxLOS
RxAIS
RxPld Unstab
Rx
TMark
RxFERF
R/W
RO
RO
RO
RO
RO
RO
RO
0
1
1
1
1
1
1
1
6.3.2.4 Performance Monitoring of the Frame
Synchronization Section, within the Receive E3
Framer block
The user can monitor the number of framing bytes
(FA1 and FA2 bytes) errors that have been detected
by the Receive E3 Framer block. This is accom-
414