MT92210 Datasheet, PDF (97/175 Pages) Zarlink Semiconductor Inc – 1023 Channel Voice Over IP Processor

Data Sheet
The format of the RX RTP HDLC channel structure is the following:
MT92210
b 15 b14 b13 b12 b11 b10 b9 b8 b7 b6 b5 b4 b3 b2 b1 b0
+0 _{A B HT 0 AR}
0
RX HDLC Stream/Buffer Index [8:0]
+2
HDLC Address [15:0]
+4
0
HDLC Control [7:0]
+6
Discharge Rate [5:0]
Header Type CRC
+8
Maximum Bucket Fill [15:0]
+A
Last Packet Local Time Stamp [23:8]
+C Last Packet Local Time Stamp [7:0] I
Current Bucket Fill [21:16]
+E
Current Bucket Fill [15:0]
+10
Received Packet Count [15:0]
+12
Received Octet Count [31:16]
+14
Received Octet Count [15:0]
Figure 52 - RX RTP HDLC Channel Structure
Field
A
B
HT
AR
RX HDLC
Stream/Buffer Index
HDLC Address
HDLC Control
Discharge Rate
Description
Clock Recovery channel A. When this field is set, an Adaptive Clock Recovery RTP
Event Structure using this packet’s sequence number and time stamp fields will be
written to the Adaptive clock recovery queue A.
Clock Recovery channel B. When this field is set, an Adaptive Clock Recovery RTP
Event Structure using this packet’s sequence number and time stamp fields will be
written to the Adaptive clock recovery queue B.
HDLC Encapsulation type. ‘0’ = HDLC Bit-wise; ‘1’ = HDLC Byte-wise.
Always Report Enable. Always generate an RX Disassembly Event Report Structure
when a packet is received and this field is set. Used for debugging only.
Index in the RX HDLC Stream/Buffer Control Table in SSRAM B.
Field that may be inserted in the HDLC packet header, depending on the Header
Type.
Field that may be inserted in the HDLC packet, depending on the Header Type.
Long term rate at which bytes can be received on this HDLC channel. The current
bucket fill is reduced at 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).
Table 35 - Fields and Description
Zarlink Semiconductor Inc.
97