
XRT94L33
xr
Rev.1.2.0.
3-CHANNEL DS3/E3/STS-1 TO STS-3/STM-1 MAPPER IC DATA SHEET
406
1.
It will indicate that it has declared the LCD defect condition by setting Bit 0 (LCD Defect Declared) and
Bits 2 and 1 (Cell Delineation Status[1:0]) bit-fields, within the “Receive ATM Cell Processor Block –
Receive ATM Status Register to “1” as depicted below.
Receive ATM Cell Processor Block – Receive ATM Status Register (Address = 0xN707)
BIT 7
BIT 6
BIT 5
BIT 4
BIT 3
BIT 2
BIT 1
BIT 0
Unused
PRBS Lock
Indicator
Cell Delineation Status[1:0]
LCD Defect
Declared
R/O
0
1
2.
It will generate the “Declaration of LCD Defect Condition” interrupt. The Receive ATM Cell Processor
block will indicate that it is declaring the “Declaration of LCD Defect Condition” Interrupt by doing the
following.
a.
Toggling the “INT*” output pin “low”.
b.
Setting Bit 0 (Declaration of LCD Defect Interrupt Status), within the “Receive ATM Cell
Processor Block – Receive ATM Interrupt Status Register – Byte 0” to “1” as depicted below.
Receive ATM Cell Processor Block – Receive ATM Interrupt Status Register – Byte 0 (Address =
0xN70B)
BIT 7
BIT 6
BIT 5
BIT 4
BIT 3
BIT 2
BIT 1
BIT 0
Receive
Cell
Insertion
Interrupt
Status
Receive
FIFO
Overflow
Interrupt
Status
Receive
Cell
Extraction
Memory
Overflow
Interrupt
Status
Receive
Cell
Insertion
Memory
Overflow
Interrupt
Status
Detection of
Correctable
HEC Byte
Error
Interrupt
Status
Detection of
Uncorrectable
HEC Byte
Error Interrupt
Status
Clearance
of LCD
Defect
Interrupt
Status
Declaration
of LCD
Defect
Interrupt
Status
RUR
0
1
The remaining discussion of the Receive ATM Cell Processor block, within this data sheet, presumes that it
(the Receive ATM Cell Processor block) is operating in the “SYNC” state and properly delineating cells.
Once the Receive ATM Cell Processor is properly delineating cells then it will proceed to route these cells
through a series of “filters”; prior to allowing these cells to be written to the RxFIFO within the Receive
UTOPIA Interface block.
Ultimately, the sequence of filtering/processing that each cell must go through is listed below in sequential
order.
HEC Byte Verification
Idle Cell Filtering
User Cell Filtering
Cell Payload De-Scrambling
The next few sections discusses each of these forms of “cell filtering”.