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CHAPTER 6 PHY FUNCTION
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Table 6-4. HEC Error Correction Mode
HECENB
CORENB
Current mode
Event
Processing
Mode to be set
No error
Cell processing
Correction mode
1-bit error detection
Error correction
Detection mode
Correction mode
Multiple bit error
detection
Cell discarded
Detection mode
No error
Cell processing
Correction mode
1-bit error detection
Cell discarded
Detection mode
0
Detection mode
Multiple bit error
detection
Cell discarded
Detection mode
No error
Cell processing
Correction mode
1-bit error detection
Cell discarded
Detection mode
Correction mode
Multiple bit error
detection
Cell discarded
Detection mode
No error
Cell processing
Correction mode
1-bit error detection
Cell discarded
Detection mode
0
1
Detection mode
Multiple bit error
detection
Cell discarded
Detection mode
No error
Cell processing
Correction mode
1-bit error detection
Cell processing
Detection mode
Correction mode
Multiple bit error
detection
Cell processing
Detection mode
No error
Cell processing
Correction mode
1-bit error detection
Cell processing
Detection mode
1
x
Detection mode
Multiple bit error
detection
Cell processing
Detection mode
(8) Descrambling of ATM cell
The data of the ATM cell is descrambled in the cell synchronization status by using the following polynomial
expression. The range of descrambling is limited to the payload of the ATM cell.
Expression
G (X) = X
43
+ 1
The user can set descramble stop mode to enable testing. Descramble stop mode can be set by using the
CSCRM bit of mode register 3 (MDR3).
(9) Discarding an idle cell (empty cell)
The
μ
PD98405 discards an ATM cell, when the higher four bytes of the ATM header are "00 00 00 01H", as
an idle cell if it receives such a cell.