XRT72L13 Datasheet, PDF (346/370 Pages) Exar Corporation – M13 MULTIPLEXER/CLEAR CHANNEL DS3 FRAMER IC

XRT72L13
M13 MULTIPLEXER/CLEAR CHANNEL DS3 FRAMER IC
REV. P1.0.6
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PRELIMINARY
“RxDS3 Interrupt Enable” Register, as illustrated be-
low.
RXDS3 INTERRUPT ENABLE REGISTER (ADDRESS = 0X12)
BIT 7
BIT 6
BIT 5
BIT 4
BIT 3
CP Bit Error
Interrupt
Enable
LOS
Interrupt
Enable
AIS
Interrupt
Enable
Idle Interrupt
Enable
FERF
Interrupt
Enable
R/W
R/W
R/W
R/W
R/W
0
0
0
0
0
BIT 2
AIC
Interrupt
Enable
R/W
0
BIT 1
OOF
Interrupt
Enable
R/W
0
BIT 0
P-Bit Error
Interrupt
Enable
R/W
0
Setting this bit-field to “1” enables this interrupt. Con-
versely, setting this bit-field to “0” disables this inter-
rupt.
Servicing the “Change of State” on Receive FERF
Interrupt
Whenever the XRT72L13 Framer IC detects this in-
terrupt, it will do all of the following.
• It will assert the “Interrupt Request” Output pin
(INT*) by driving it “high”.
• It will set Bit 3 (FERF Interrupt Status), within the
“Rx DS3 Interrupt Status” Register, to “1”, as indi-
cated below.
•
RXDS3 INTERRUPT STATUS REGISTER (ADDRESS = 0X13)
BIT 7
BIT 6
BIT 5
BIT 4
BIT 3
BIT 2
BIT 1
BIT 0
CP-Bit Error
Interrupt
Status
LOS
Interrupt
Status
AIS
Interrupt
Status
Idle Interrupt
Status
FERF
Interrupt
Status
AIC
Interrupt
Status
OOF
Interrupt
Status
P-Bit Error
Interrupt
Status
RUR
RUR
RUR
RUR
RUR
RUR
RUR
RUR
0
0
0
0
1
0
0
0
Whenever the Terminal Equipment encounters a
“Change in FERF Condition on Receive” Interrupt, it
should do the following.
1. It should determine the current state of the
“FERF” condition. Recall, that this interrupt can
generated, whenever the XRT72L13 Framer
RXDS3 STATUS REGISTER (ADDRESS = 0X11)
BIT 7
BIT 6
BIT 5
BIT 4
Reserved
RxFERF
RO
RO
RO
RO
0
0
0
0
declares or clears the FERF condition. Hence,
the user can determine the current state of the
FERF condition by reading the state of Bit 5 (RxI-
dle), within the “RxDS3 Configuration & Status”
Registers, as illustrated below
BIT 3
RxAIC
RO
0
BIT 2
RO
0
BIT 1
RxFEBE[2:0]
RO
0
BIT 0
RO
0
4.3.6.2.6 The “Change of State” of Receive AIC
Interrupt
If the “Change of State of Receive AIC” Interrupt is
enabled, then the XRT72L13 Framer IC will generate
an interrupt, anytime the “Receive DS3 Framer” block
has detected a change in the value of the “AIC” bit,
within the “incoming” DS3 data stream.
Enabling and Disabling the “Change of State of
Receive AIC Interrupt:
The user can enable or disable the “Change of State
on Receive AIC” Interrupt, by writing the appropriate
value into Bit 2 (AIC Interrupt Enable) within the
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