
XRT7250
á
DS3/E3 FRAMER IC
REV. 1.1.1
330
the Rx E3 Interrupt Enable Register - 2, as indicated
below.
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 Framing Error Interrupt
Whenever the XRT7250 Framer IC detects this inter-
rupt, it will do the following.
It will assert the Interrupt Request output pin (INT),
by driving it “High”.
It will set the Bit 1 (Framing Error Interrupt Status),
within the RxE3 Interrupt Status Register - 2 as
indicated below.
Whenever the Terminal Equipment encounters the
Detection of Framing Error Interrupt, it should do the
following.
It should read the contents of the PMON Framing
Bit/Byte Error Count Registers (located at
Addresses 0x52 and 0x53) in order to determine
the number of Framing errors that have been
received by the XRT7250 Framer IC.
5.3.6.2.9
The Receipt of New LAPD Message
Interrupt
If the Receive LAPD Message Interrupt is enabled,
then the XRT7250 Framer IC will generate an inter-
rupt anytime the Receive HDLC Controller block has
received a new LAPD Message frame from the Re-
mote Terminal Equipment, and has stored the con-
tents of this message into the Receive LAPD Mes-
sage buffer.
Enabling/Disabling the Receive LAPD Message
Interrupt
The user can enable or disable the Receive LAPD
Message Interrupt by writing the appropriate data into
Bit 1 (RxLAPD Interrupt Enable) within the Rx E3
LAPD Control Register, as indicated below.
RXE3 INTERRUPT ENABLE REGISTER - 2 (ADDRESS = 0X13)
BIT 7BIT 6BIT 5BIT 4BIT 3BIT 2BIT 1BIT 0
Not Used
FERF
Interrupt
Enable
BIP-4 Error
Interrupt
Enable
Framing Error
Interrupt
Enable
Not Used
R/W
RO
R/W
RO
00
000
0
X
0
RXE3 INTERRUPT STATUS REGISTER - 2 (ADDRESS = 0X15)
BIT 7BIT 6BIT 5BIT 4BIT 3BIT 2BIT 1BIT 0
Not Used
FERF
Interrupt
Status
BIP-4
Error
Interrupt
Status
Framing
Error
Interrupt
Status
Not Used
RO
RUR
00
000
RXE3 LAPD CONTROL REGISTER (ADDRESS = 0X18)
BIT 7BIT 6BIT 5BIT 4BIT 3BIT 2BIT 1BIT 0
Not Used
RxLAPD
Enable
RxLAPD
Interrupt Enable
RxLAPD
Interrupt Enable
RO
R/W
RUR
00000
0