MT92220BG Zarlink Semiconductor, MT92220BG Datasheet - Page 29

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

Data Sheet
Handle queues are stored in SSRAM C. Each handle occupies a block of 16 bytes. Handle format is shown in
Figure 7.
RX packets received from the packet assembly module are contained in a 2K byte internal memory. Once the full
packet has been received, it is transferred to the SDRAM in block form. This internal buffer is large enough to
contain an entire packet of up to 1500 bytes in length (+ link overhead). In addition to the packet memory, a small
(128 bytes) handle memory contains the handles to these packets, indicating their length, base address and
+C
+0
+4
+8
RTD: RouTing Destination; bit to indicate next destination
SOP: Start Of Packet Handle is the index of the first block in Packet Block Memory
BIP:
EOP: End Of Packet Handle is the index of the last block in Packet Block Pool
TPL: Total Packet Length is the total length of the packet in octets (max 65 535)
Basic Handle Format
b31
HQB : Handle Queue Base address
HRP : Handle Read Pointer
HWP : Handle Write Pointer
b30
HQB
Blocks In Packet is the number of blocks used to store the complete packet
b29
+10
+20
+30
+40
+50
+60
+0
b28
“xxxxxxxx1” = TX Link A Raw Cell Buffer 0
“xxxxxxx1x” = TX Link A Raw Cell Buffer 1
“xxxxxx1xx” = TX Link A Raw Cell Buffer 2
“xxxxx1xxx” = TX Link A Raw Cell Buffer 3
“xxxx1xxxx” = TX Link B Raw Cell Buffer 0
“xxx1xxxxx” = TX Link B Raw Cell Buffer 1
“xx1xxxxxx” = RX CPU Raw Cell Buffer
“x1xxxxxxx” = AAL2 Raw Cell Buffer (not used for OAM packets)
“100000000” = AAL5 VC (not used for OAM packets)
b27
Blocks in Packet[10:0]
b26
Handle Queue (FIFO)
Figure 7 - Handle Queue and Handle Format
b25
b24
RTD
b23
b22
Figure 8 - Basic Handle Format
b21
b20
Zarlink Semiconductor Inc.
b19
b18
b17
b16
b15
b14
b13
b12
b11
SOP Handle[18:0]
EOP Handle[18:0]
Total Packet Length[15:0]
b10
b9
b8
b7
b6
HRP
HWP
b5
b4
b3
b2
b1
b0
MT92220
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