
XRT7245
DS3 UNI FOR ATM
á
PRELIMINARY
REV. 1.03
238
The Rx DS3 FEAC Interrupt Enable/Status Register
consists of 5 active bit-fields. However, only 4 of
these bit fields are relevant to interrupt processing.
Bit 0—Rx FEAC Valid Interrupt Status
A “1” in this bit-field indicates that a newly received
FEAC Message has been validated by the Receive
FEAC Processor. The Receive FEAC Processor will
validate a FEAC Message if both of the following
conditions are met.
The same message has been received during 8
out of the last 10 transmission from the Far End
Transmitter, and
This new, incoming FEAC Message is different
from the previous validated FEAC message.
1.
2.
Bit 1—Rx FEAC Valid Interrupt Enable
This bit allows the user to enable/disable the “Rx FEAC
Valid” Interrupt. Writing a “1” to this bit-field enables
this interrupt. Whereas, writing a “0” disables this in-
terrupt. The value of this bit field is “0” following
power up or reset.
Bit 2—Rx FEAC Removal Interrupt Status
A “1” in this bit-field indicates that the last “validated”
FEAC Message has now been removed by the
Receive FEAC Processor. The Receive FEAC
Processor will remove a validated FEAC message if
3 out of the last 10 received FEAC messages differ
from this valid FEAC message.
Bit 3—Rx FEAC Removal Interrupt Enable
This bit field allows the user to enable/disable the “Rx
FEAC Removal” interrupt. Writing a “1” to this bit
enables this interrupt. Likewise, writing a “0” to this
bit-field disables this interrupt.
7.1.2.9.3
The LAPD Receiver also has the ability to generate
an interrupt to the μC/μP when it (the LAPD Receiver)
has finished receiving an incoming LAPD message.
The purpose of this interrupt is to inform the μC/μP
that there is a newly received LAPD message that is
ready to be read by the μC/μP Interrupt servicing of
this type of interrupt is supported via the Rx DS3
LAPD Status Register. The features associated with
this register are described below.
LAPD Receiver Interrupts
Rx DS3 LAPD Control Register
The Rx DS3 LAPD Control register consists of 8 active
bit-fields. However, only 2 of these 8 are related to
servicing the LAPD Receiver-related interrupts. The
bit format of this register is presented below.
Bit 0—RxLAPD Interrupt Status
A “1” in this bit-field indicates that the LAPD Receiver
has received a full-LAPD message frame, and that
the information portion of this LAPD frame is available
in the “Receive LAPD Message” buffer for reading by
the local μC/μP
Note:
This interrupt does not indicate that this new LAPD
Message is valid or “error-free”. The user is advised to ver-
ify that error-free reception occurred, by reading Bit 2 of the
Rx DS3 LAPD Status Register.
Rx DS3 FEAC Interrupt Enable/Status Register (Address = 13h)
B
IT
7
B
IT
6
B
IT
5
B
IT
4
B
IT
3
B
IT
2
B
IT
1
B
IT
0
Unused
Unused
Unused
FEAC
Valid
RxFEAC Remove
Interrupt Enable
RxFEAC
Remove
Interrupt Status
RxFEAC Valid
Interrupt
Enable
RxFEAC Valid
Interrupt
Status
R/O
R/O
R/O
R/O
R/W
RUR
R/W
RUR
Rx DS3 LAPD Control Register (Address = 14h)
B
IT
7
B
IT
6
B
IT
5
B
IT
4
B
IT
3
B
IT
2
B
IT
1
B
IT
0
Enable5
F(4)
Enable5
F(3)
Enable5
F(2)
Enable5
F(1)
Enable5
F(0)
RxLAPD
Enable
RxLAPD Interrupt
Enable
RxLAPD Interrupt
Status
R/W
R/W
R/W
R/W
R/W
R/W
R/W
RUR