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PRELIMINARY
XRT79L71
480
REV. P2.0.0
1-CHANNEL DS3/E3 CLEAR-CHANNEL FRAMERLIU COMBO - CC/HDLC ARCHITECTURE
STEP 7b - Enable the Transmit DS3/E3 Framer block Interrupts - At the Block Level.
This step is accomplished by setting Bit 1 (Transmit DS3/E3 Framer Block Interrupt Enable), within the Block
Interrupt Enable Register to "1", as illustrated below.
This step enables the Transmit DS3/E3 Framer block for interrupt generation, at the Block Level.
STEP 7c - Enable the Transmit LAPD Interrupt at the Source Level.
This step is accomplished by setting Bit 1 (Transmit LAPD Interrupt Enable), within the Transmit E3 LAPD
Status/Interrupt Register to "1", as illustrated below.
STEP 8 - Command the Transmit LAPD Controller to begin its transmission.
At this point, it is finally time to command the Transmit LAPD Controller to do its job and transmit the loaded
PMDL Message to the remote terminal equipment.
The user accomplishes this by inducing a "0" to "1"
transition, within Bit 3 (Initiate Transmission of LAPD/PMDL Message) in the Transmit E3 LAPD Status/
Interrupt Register, as depicted below.
Once the user executes this step, then the Transmit LAPD Controller will proceed to do the following.
a. It will parse through the contents of the Transmit LAPD Message buffer and will "zero"-stuff the payload
portion of the outbound PMDL Message.
Block Interrupt Enable Register (Address = 0x1104)
BIT 7
BIT 6
BIT 5
BIT 4
BIT 3
BIT 2
BIT 1
BIT 0
Receive
DS3/E3
Framer Block
Interrupt
Enable
Receive PLCP
Processor
Block Interrupt
Enable
Unused
Transmit
DS3/E3
Framer Block
Interrupt
Enable
One Second
Interrupt
Enable
R/W
R/O
R/W
X
0
1
X
Transmit E3 LAPD Status/Interrupt Register (Address = 0x1134)
BIT 7
BIT 6
BIT 5
BIT 4
BIT 3
BIT 2
BIT 1
BIT 0
Unused
Initiate
Transmission of
LAPD/PMDL
Message
Transmit LAPD
Controller Busy
Transmit LAPD
Interrupt Enable
Transmit LAPD
Interrupt Status
RO
R/W
RO
R/W
RUR
0
1
0
Transmit E3 LAPD Status/Interrupt Register (Address = 0x1134)
BIT 7
BIT 6
BIT 5
BIT 4
BIT 3
BIT 2
BIT 1
BIT 0
Unused
Initiate
Transmission of
LAPD/PMDL
Message
Transmit LAPD
Controller Busy
Transmit LAPD
Interrupt Enable
Transmit LAPD
Interrupt Status
RO
R/W
RO
R/W
RUR
0
0->1
0
1
0