mt90503 Zarlink Semiconductor, mt90503 Datasheet - Page 73

• Manufacturer Part Number: mt90503
• Description: 2048vc Aal1 Sar
• Manufacturer: Zarlink Semiconductor

LE
AE
PE
Max Used
Bytes in
RX
Circular
Buffer
Payload
Size
PBI
P-Byte
Counter
Current
Entry
Field
Name of Field
Cell Loss and
Insertion Error
Report Enable
AAL1 Byte
Report Enable
P-Byte Error
Report Enable
Max Used
Bytes in RX
Circular Buffer
Payload Size
P-Byte
Initialization
P-Byte
Counter
Current Entry
Table 23 - Description of the Fields for the RX_SAR Structure (continued)
Offset/Bits Used
+2/b2
+2/b1
+2/b0
+4/b15:b6
+4/b5:b0
+6/b15
+6/b14:b0
+8/b11:b0
Byte Address
Zarlink Semiconductor Inc.
MT90503
When set, single cell losses, multiple cell losses and cell
misinsertions will generate an RX_SAR Error Report
Structure (Figure 32) in the error FIFO in control memory.
When set, AAL1 CRC-3 and CRC-3/Seq Num parity errors
will generate an RX_SAR Error Report Structure (Figure 32)
in the error FIFO in control memory.
When set, p-byte parity errors, p-byte absent and p-byte
framing errors will generate an RX_SAR Error Report
Structure (Figure 32) in the error FIFO in external control
memory.
This field indicates the range of valid positions in bytes of the
rx_sar_write_pnt relative to the tdm_rx_read_pnt before a
cell is received. In no case can this value be 0.
For fully-filled cells, regardless of type, the payload size field
is 30h. For partially-filled cells, the payload size indicates the
number of TDM bytes in each ATM cell. The field range is
from 4h to 2Fh.
Note: 2Fh is an illegal value for partially-filled AAL1cells
For partially-filled AAL5 VTOA, this field must be set to 8h,
10h, 18h, 20h, or 28h.
Initialized to ’0’ by software.
This field is a counter used to detect p-byte framing errors.
When a p-byte is detected, this counter is loaded with the
p-byte’s value. Each time a TDM byte is received, the
counter is decremented. When the counter reaches the
Current Entry it should be reset to the First Entry and the
rx_sar_write_pnt should point to the beginning of the
multiframe if applicable. When it decrements below 0, the
counter resets to its maximum. Any time a p-byte is
received, its value should match the value in this field, or a
p-byte framing error will be detected.
currently writing to the circular buffers. The current entry is
defined as being the offset from the 8 KB boundary
containing the structure and the “TX/RX Circular Buffer
Pointer” being read from the structure. Current Entry is
initialised to the value of First Entry, increments up to Last
Entry, and then wraps around to First Entry.
This field should be initialised by software to 0Bh.
Note: This field should not be written to while the VC is
active.
Current Entry indicates which TDM channel the RX_SAR is
73
Description of Field
Data Sheet