MT92220 Zarlink Semiconductor, MT92220 Datasheet - Page 124

• Manufacturer Part Number: MT92220
• Description: 1023 Channel Voice Over IP/AAL2 Processor
• Manufacturer: Zarlink Semiconductor

124
Min Slip
IIL
I2
Last UUI
Last Packet Remote
Time Stamp
Total Slip Offset
Delta
AAL2 Interchip
Synchronization
Delta
Desired
Remote-Local Time
Stamp Delta
Reserved
Note
Field
This field define how many frames of lost data are considered enough to identify the gap
as a silence period and will cause the Total Slip Offset Delta to be reset when the RSL bit
is set.
“000” = 16 frames;
“001” = 32 frames;
“010” = 64 frames;
“011” = 128 frames;
“100” = 256 frames;
“101” = 512 frames;
“110” = 1024 frames;
“111” = 2048 frames.
Total Slip Offset Delta will be set to the shortest allowed delay between the remote and
local time stamp, plus the Init Lead programmed in the RX AAL2 Disassembly Extension
Structure. When this bit is cleared, the Desired Remote/Local Time Stamp Delta will be
assumed to be correct and normal underrun/overrun slipping will take place.
Init bit. This bit must be written to zero by software when the structure is initialized. When
the first packet is processed by this structure, the I2 bit will be written back to ‘1’ by the
hardware.
UUI value received in the last processed packet. Received packets will have their UUI
value compared to this UUI value to establish when they were sent relative to the last
processed packet. UUI values are always assumed to stay constant or to increment vs
previously received packets.
32-bit time stamp (created via an extension of the UUI field) of the packet sent by the
remote end. The starting point of this time stamp is arbitrary.
This value is the current number of frames that were either added or dropped due to
overruns and underruns. A positive number represents overruns and a negative number
represents underruns. Note that underrun frames and overruns frames cancel-out in this
field.
This field is reserved for future use and should always be set zero.
This field contains the desired local/remote time stamp delta to be applied to all received
packets. A time stamp delta of zero means that a packet received with time stamp of
zero would see its first byte output on the bus when the local bus time stamp is zero. This
field should be written to zero at initialization time.
Write 0 for normal operation.
all remote/local timestamp deltas are calculated with the following equation: delta =
remote_packet_timestamp - local_bus_timestamp;
Init with Init Lead. When this bit is set and a packet is received with the I2 bit cleared, the
Table 49 - Fields and Description (continued)
Zarlink Semiconductor Inc.
Description