PXB4219 Datasheet, PDF (52/290 Pages) Infineon Technologies AG – IWE8 Interworking Element for 8 E1/T1 Lines

PXB4219 / PXB4220 / PXB4221
Operational Description
.
No error
detected
Detection
Mode
Error detected
Cell discarded
Figure 10 HEC Detection According to ATM Forum
No discarding of HEC errored cells as an option is available and selectable via bit
“a_hec_mode” in the register acfg (Chapter 7.2). In this case an errored HEC is
indicated by setting the most significant bit in the UDF field at the UTOPIA receive
interface.
4.2.1.3 Cell Payload Descrambling
ITU-T I.432.3 [34] recommends the self-synchronizing scrambler x⁴³+1 for payload
scrambling at E1 datarates. For T1 no scrambling is recommended.
The self-synchronizing scrambler function is implemented in the device. It can be
disabled per port by the x43_descrambling bit in the “ATM Receive Reference Slot” in
RAM1.
4.2.1.4 Idle, Physical Layer or Unassigned Cell Deletion
According to ITU-T I.361 [30], idle cells, physical layer OAM cells and cells reserved for
use by the physical layer are not passed to the ATM layer at the UNI.
Data Sheet
52
2002-05-06