XRT72L56 Datasheet, PDF (366/486 Pages) Exar Corporation – SIX CHANNEL DS3/E3 FRAMER IC WITH HDLC CONTROLLER

XRT72L56
SIX CHANNEL DS3/E3 FRAMER IC WITH HDLC CONTROLLER
REV. P1.1.2
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PRELIMINARY
Enabling and Disabling the Detection of FEBE
Event Interrupt
The user can enable or disable the Detection of BIP-4
Error’ interrupt by writing the appropriate value into
Bit 2 (BIP-4 Interrupt Enable) within the Rx E3 Inter-
rupt Enable Register - 2, as indicated below.
RXE3 INTERRUPT ENABLE REGISTER - 2 (ADDRESS = 0X13)
BIT 7
BIT 6
BIT 5
BIT 4
BIT 3
BIT 2
BIT 1
BIT 0
Not Used
FERF
Interrupt
Enable
BIP-4 Error Framing Error
Interrupt
Interrupt
Enable
Enable
Not Used
R/W
RO
RO
RO
R/W
R/W
R/W
RO
0
0
0
0
0
X
0
0
Setting this bit-field to “1” enables this interrupt. Con-
versely, setting this bit-field to “0” disables this inter-
rupt.
Servicing the Detection of the BIP-4 Error Inter-
rupt
Whenever the XRT72L56 Framer IC detects this in-
terrupt, it will do the following.
• It will assert the Interrupt Request output pin (INT),
by driving it “High”.
• It will set the Bit 2 (BIP-4 Interrupt Status), within
the RxE3 Interrupt Status Register - 2 as indicated
below.
RXE3 INTERRUPT STATUS REGISTER - 2 (ADDRESS = 0X15)
BIT 7
BIT 6
BIT 5
BIT 4
BIT 3
BIT 2
BIT 1
BIT 0
Not Used
FERF
Interrupt
Status
BIP-4
Error
Interrupt
Status
Framing
Error
Interrupt
Status
Not Used
RO
RO
RO
RO
RUR
RUR
RUR
RUR
0
0
0
0
0
1
0
0
Whenever the Terminal Equipment encounters the
Detection of BIP-4 Error Interrupt, it should do the fol-
lowing.
• It should read the contents of the PMON Parity
Error Event Count Registers (located at Addresses
0x54 and 0x55) in order to determine the number of
BIP-4 Errors that have been received by the
XRT72L56 Framer IC.
5.3.6.2.8 The Detection of Framing Error Inter-
rupt
If the Detection of Framing Error Interrupt is enabled,
then the XRT72L56 Framer IC will generate an inter-
rupt, anytime the Receive E3 Framer block has re-
ceived an E3 frame with an incorrect FAS pattern val-
ue.
Enabling and Disabling the Detection of FEBE
Event Interrupt
The user can enable or disable the Detection of
Framing Error’ interrupt by writing the appropriate val-
ue into Bit 1 (Framing Error Interrupt Enable) within
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