MT92220BG Zarlink Semiconductor, MT92220BG Datasheet - Page 128

• Manufacturer Part Number: MT92220BG
• Description: Description = 1023 Channel Voice Over IP/AAL2 Processor ;; Package Type = Epbga ;; No. Of Pins = 608
• Manufacturer: Zarlink Semiconductor

128
Discharge Rate
Header Type
CRC
Maximum Bucket Fill
CBF
Last Packet Local Time
Stamp
I
Received Packet Count
Received Octet Count
Field
Long term rate at which bytes can be received on this HDLC channel. The current
bucket fill is reduced by this rate. The rate is defined as a number of bytes per frame
that can be sent on the HDLC stream (including all forms of HDLC framing). This is a
floating point number; it has two bits of mantissa (excluding the hidden leading ‘1’)
and 4 bits of exponent. Zero is not a legal value. The minimum rate is 4 kbps, which
is defined as mantissa = “100” and exponent = “0001”. So to calculate the rate, the
following equation can be used: 4 kbps * (mantissa/8) * (2^exponent).
Can be set to:
"000"=Plain;
"001"=One byte address;
"010"=Two byte address;
"011"=One byte address + Control;
"100"=Two byte address + Control;
others = reserved.
Note that the first byte of HDLC packet payload is always used to carry the UUI value
of the AAL2 packet (in the high bits of the byte).
‘0’ = no CRC bytes will be appended to the HDLC packet; ‘1’ = a 16-bit CRC-16
(otherwise known as CRC-CCITT) will be inserted at the end of the HDLC packet.
Up to this many bytes can be contained in the “policing bucket” of this HDLC channel
before packet discarding takes place. Largest value is 0x0000 (which means 65536
bytes), smallest value is 0x1 (which means 1 byte).
Current Bucket Fill. Current fill of the “policing bucket” in 1/64th of a byte. This field
should be initialized to all zeros by software.
Time stamp in frames of the last received packet used to determine the time delta
between the reception of HDLC packets. Used to discharge the Current Bucket Fill.
Initialized bit. Written to zero by software channel initialization. Written to ‘1’ by
hardware as soon at the first packet is received on this channel.
Total number of packets received on this channel so far. Every packet that gets to
this structure will be included.
Total number of bytes received on this channel so far. Every packet that gets to this
structure will be included. It will include all payload byte plus 8 bytes of packet
overhead (i.e. LI+9).
Table 51 - Fields and Description (continued)
Zarlink Semiconductor Inc.
Description