XRT72L50 Datasheet, PDF (250/471 Pages) Exar Corporation – SINGLE CHANNEL DS3/E3 FRAMER IC WITH HDLC CONTROLLER

XRT72L50
SINGLE CHANNEL DS3/E3 FRAMER WITH HDLC CONTROLLER
REV. 1.2.1
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To enable or disable the Receive FEAC Message - Removal Interrupt, write the appropriate data into Bit 3
(RxFEAC Remove Interrupt Enable) within the RxDS3 FEAC Interrupt Enable/Status Register, as indicated
below.
RxDS3 FEAC Interrupt Enable/Status Register (Address = 0x17)
BIT 7
RO
0
BIT 6
Not Used
RO
0
BIT 5
RO
0
BIT 4
FEAC Valid
RO
0
BIT 3
RxFEAC
Remove
Interrupt
Enable
R/W
X
BIT 2
RxFEAC
Remove
Interrupt
Status
RUR
0
BIT 1
RxFEAC
Valid
Interrupt
Enable
R/W
X
BIT 0
RxFEAC
Valid
Interrupt
Status
RUR
0
Setting this bit-field to “1” enables this interrupt. Conversely, setting this bit-field to “0” disables this interrupt.
Servicing the Receive FEAC Message - Validation Interrupt.
Whenever the XRT72L50 Framer IC generates this interrupt, it will do the following.
• It will assert the Interrupt Request output pin (Int) by driving it "Low".
• It will set Bit 2 (RxFEAC Remove Interrupt Status), within the RxDS3 FEAC Interrupt Enable/Status Register
to “1”, as indicated below.
RxDS3 FEAC Interrupt Enable/Status Register (Address = 0x17)
BIT 7
RO
0
BIT 6
Not Used
RO
0
BIT 5
RO
0
BIT 4
FEAC Valid
RO
0
BIT 3
RxFEAC
Remove
Interrupt
Enable
R/W
0
BIT 2
RxFEAC
Remove
Interrupt
Status
RUR
0
BIT 1
RxFEAC
Valid
Interrupt
Enable
R/W
1
BIT 0
RxFEAC
Valid
Interrupt
Status
RUR
1
• It will delete the contents of the most recently validated FEAC Message from the Rx DS3 FEAC Register, as
indicated below.
RXDS3 FEAC REGISTER (ADDRESS = 0X16)
BIT 7
Not Used
RO
0
BIT 6
RO
X
BIT 5
RO
X
BIT 4
BIT 3
RxFEAC[5:0]
RO
RO
X
X
BIT 2
RO
X
BIT 1
RO
X
BIT 0
Not Used
RO
0
4.3.6.2.11 The Completion of Reception of a LAPD Message Interrupt
If the Completion of Reception of a LAPD Message interrupt is enabled, then the XRT72L50 Framer IC will
generate an interrupt anytime the Receive HDLC Controller block has received a new LAPD Message buffer,
from the Remote Terminal Equipment, and has stored the contents of this message in the Receive LAPD
Message Buffer.
Enabling/Disable the Receive LAPD Message Interrupt
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