mt90502ag2 Zarlink Semiconductor, mt90502ag2 Datasheet - Page 46

• Manufacturer Part Number: mt90502ag2
• Description: Multi-channel Aal2 Sar
• Manufacturer: Zarlink Semiconductor

2.2.4.3
TDM Frame Buffer Notes:
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•
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Stream 1 Timeslot 0
Stream 0 Timeslot 0
TDM Frame Buffer is an internal
Bytes are taken from the TDM Frame
TSSTs for which no TX CAM entry
memory inaccessible to the user. It
contains the latest byte to enter the chip
from each TSST on the H.100/H.110
bus.
Buffer and treated according to the TX
CAM entry for that TSST.
exists are ignored.
Stream 31
Timeslot 0
Timeslot 127
Timeslot 127
Timeslot 127
TDM Frame Buffer
Timeslot 1
Timeslot 1
Timeslot 1
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TDM Frame Buffer
ADPCM byte
HDLC byte
PCM byte
LLL byte
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8000h+0Ah*x
to LLL Buffer.
8000h+0Ah*z
CPS-Packet Circular Buffer Notes:
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Zero Extractor
Figure 18 - TDM Frame Buffer
Each buffer is 256 bytes long.
N consecutive circular buffers exist in SSRAM (N = number
of channels, as set by sar_capacity -- see register 0240h).
Location of buffers within SSRAM is dependent on
sar_capacity.
Buffers are in order by HDLC/PCM channel number (see
TX CAM).
When a CPS-Packet is assembled, data from the buffer is
placed in an ATM cell and the CPS-Packet read pointer
(CPSP Buf RP) in the assembly structure is adjusted.
structure -- see Figure 13
History Bits & Valid [7:0]
Zarlink Semiconductor Inc.
CPS-Packet assembly
Partial Byte Storage [7:1]
structure -- see Figure 12
CPS-Packet assembly
MT90502
46
TX SAR CPSP Buf RP Write Back
+y*100h
+z*100h
+x*100h
+0h
CPS-Packet Circular Buffers
circular buffer N-1
circular buffer x
circular buffer y
circular buffer z
CPS-Packet
CPS-Packet
CPS-Packet
CPS-Packet
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Notes:
• Channels dedicated
• ADPCM information
• CPS-Packet assem-
• LLL (Low latency
• The TX SAR can be
to HDLC (indicated
by the CPS-Packet
assembly structure
for that channel)
undergo zero-extrac-
tion before being
placed in the correct
CPS-Packet circular
buffer.
is accumulated in the
CPS-Packet assem-
bly structure for that
channel until an
entire byte has been
collected.
bly structures for
PCM channels are
consulted to direct
PCM bytes to the
correct CPS-Packet
circular buffer
loopback) bytes are
placed directly into
the RX TDM Frame
Buffer to exit the chip
on the H.100/H.110
bus.
configured to alter
the read pointer on a
per-channel basis.
Data Sheet