- 您現(xiàn)在的位置：買賣IC網(wǎng) > PDF目錄293778 > 28230-13 (CONEXANT SYSTEMS) ATM SEGMENTATION AND REASSEMBLY DEVICE, PQFP208 PDF資料下載
參數(shù)資料
| 型號(hào)： | 28230-13 |
| 廠商： | CONEXANT SYSTEMS |
| 元件分類： | 數(shù)字傳輸電路 |
| 英文描述： | ATM SEGMENTATION AND REASSEMBLY DEVICE, PQFP208 |
| 封裝： | PLASTIC, MQFP-208 |
| 文件頁(yè)數(shù)： | 224/237頁(yè) |
| 文件大小： | 3214K |
| 代理商： | 28230-13 |
第1頁(yè)第2頁(yè)第3頁(yè)第4頁(yè)第5頁(yè)第6頁(yè)第7頁(yè)第8頁(yè)第9頁(yè)第10頁(yè)第11頁(yè)第12頁(yè)第13頁(yè)第14頁(yè)第15頁(yè)第16頁(yè)第17頁(yè)第18頁(yè)第19頁(yè)第20頁(yè)第21頁(yè)第22頁(yè)第23頁(yè)第24頁(yè)第25頁(yè)第26頁(yè)第27頁(yè)第28頁(yè)第29頁(yè)第30頁(yè)第31頁(yè)第32頁(yè)第33頁(yè)第34頁(yè)第35頁(yè)第36頁(yè)第37頁(yè)第38頁(yè)第39頁(yè)第40頁(yè)第41頁(yè)第42頁(yè)第43頁(yè)第44頁(yè)第45頁(yè)第46頁(yè)第47頁(yè)第48頁(yè)第49頁(yè)第50頁(yè)第51頁(yè)第52頁(yè)第53頁(yè)第54頁(yè)第55頁(yè)第56頁(yè)第57頁(yè)第58頁(yè)第59頁(yè)第60頁(yè)第61頁(yè)第62頁(yè)第63頁(yè)第64頁(yè)第65頁(yè)第66頁(yè)第67頁(yè)第68頁(yè)第69頁(yè)第70頁(yè)第71頁(yè)第72頁(yè)第73頁(yè)第74頁(yè)第75頁(yè)第76頁(yè)第77頁(yè)第78頁(yè)第79頁(yè)第80頁(yè)第81頁(yè)第82頁(yè)第83頁(yè)第84頁(yè)第85頁(yè)第86頁(yè)第87頁(yè)第88頁(yè)第89頁(yè)第90頁(yè)第91頁(yè)第92頁(yè)第93頁(yè)第94頁(yè)第95頁(yè)第96頁(yè)第97頁(yè)第98頁(yè)第99頁(yè)第100頁(yè)第101頁(yè)第102頁(yè)第103頁(yè)第104頁(yè)第105頁(yè)第106頁(yè)第107頁(yè)第108頁(yè)第109頁(yè)第110頁(yè)第111頁(yè)第112頁(yè)第113頁(yè)第114頁(yè)第115頁(yè)第116頁(yè)第117頁(yè)第118頁(yè)第119頁(yè)第120頁(yè)第121頁(yè)第122頁(yè)第123頁(yè)第124頁(yè)第125頁(yè)第126頁(yè)第127頁(yè)第128頁(yè)第129頁(yè)第130頁(yè)第131頁(yè)第132頁(yè)第133頁(yè)第134頁(yè)第135頁(yè)第136頁(yè)第137頁(yè)第138頁(yè)第139頁(yè)第140頁(yè)第141頁(yè)第142頁(yè)第143頁(yè)第144頁(yè)第145頁(yè)第146頁(yè)第147頁(yè)第148頁(yè)第149頁(yè)第150頁(yè)第151頁(yè)第152頁(yè)第153頁(yè)第154頁(yè)第155頁(yè)第156頁(yè)第157頁(yè)第158頁(yè)第159頁(yè)第160頁(yè)第161頁(yè)第162頁(yè)第163頁(yè)第164頁(yè)第165頁(yè)第166頁(yè)第167頁(yè)第168頁(yè)第169頁(yè)第170頁(yè)第171頁(yè)第172頁(yè)第173頁(yè)第174頁(yè)第175頁(yè)第176頁(yè)第177頁(yè)第178頁(yè)第179頁(yè)第180頁(yè)第181頁(yè)第182頁(yè)第183頁(yè)第184頁(yè)第185頁(yè)第186頁(yè)第187頁(yè)第188頁(yè)第189頁(yè)第190頁(yè)第191頁(yè)第192頁(yè)第193頁(yè)第194頁(yè)第195頁(yè)第196頁(yè)第197頁(yè)第198頁(yè)第199頁(yè)第200頁(yè)第201頁(yè)第202頁(yè)第203頁(yè)第204頁(yè)第205頁(yè)第206頁(yè)第207頁(yè)第208頁(yè)第209頁(yè)第210頁(yè)第211頁(yè)第212頁(yè)第213頁(yè)第214頁(yè)第215頁(yè)第216頁(yè)第217頁(yè)第218頁(yè)第219頁(yè)第220頁(yè)第221頁(yè)第222頁(yè)第223頁(yè)當(dāng)前第224頁(yè)第225頁(yè)第226頁(yè)第227頁(yè)第228頁(yè)第229頁(yè)第230頁(yè)第231頁(yè)第232頁(yè)第233頁(yè)第234頁(yè)第235頁(yè)第236頁(yè)第237頁(yè)
74
3.0 Functional Description
3.5 Reassembly Coprocessor
Bt8230
ATM Segmentation and Reassembly Controller—SAR
N8230DS1F
3.5.2 Hashing
The Bt8230 implements a hash algorithm to locate the appropriate RSM VCC
table entry for incoming ATM cells. During reassembly, the Bt8230 looks at the
header of each incoming ATM cell to determine the connection (VCC) to which
the cell belongs. This information is then used to establish where in the host
memory the current reassembly buffer for this connection resides. The pointer to
that buffer location (CBUFF_ADDR) is one of the fields in the reassembly VCC
table entry for that connection. Because ATM cells will be received in an
unknown order from the line, the Bt8230 must manage several incoming data
streams and determine the VCC to which each cell belongs.
3.5.2.1 Hashing
Algorithm
The Bt8230 hashing algorithm passes the 24-bit VPI/VCI pair received from the
line through a truncating function. The hardware hashing function computes the
hash table index as follows:
({VPI[7:0],VCI[15:12]} ^ VCI[11:0]) & (2
TAB_SIZE–1)
Bits 0 through 7 of the VPI are concatenated with bits 12 through 15 of the
VCI to form a 12-bit field. This field is then exclusive-ORed with bits 0 through
11 of the VCI. The result is masked with a bitmask generated from the
TAB_SIZE field of the Reassembly Control Register [RSM_CTRL; 0x70]. This
function shortens the identifier to an N-bit field, where N is between 0 and 14.
The Bt8230 then multiplies the N-bit offset by four and adds the result to the con-
tents of the Reassembly Hash Table Base Register [RSM_HBASE; 0x7C] to pro-
duce the actual address of a pointer to a hash bucket chain. When TAB_SIZE is
equal to 14, a special 14-bit hash index function is enabled. The hash table index
is calculated as follows:
({VPI[7:0],VCI[15:14],’0000’} ^ VCI[13:0])
The hash bucket chain is processed sequentially for a hash bucket match. The
hash bucket index comparator computes the logical-AND of the 32-bit MASK
field of a hash bucket read from memory with the 32-bit ATM header and com-
pares the result with the 32-bit HEADER field in the same hash bucket to gener-
ate a match signal. The match signal is used by the reassembly coprocessor to
determine whether the required hash bucket has been found. If a match is
obtained, the current hash bucket is used to process the cell; otherwise, the reas-
sembly coprocessor reads a pointer to the next sequential bucket in the list from
the NEXT field and repeats the matching process. If NEXT contains a null (zero)
pointer, the end of the list is assumed to have been reached; the matching is then
declared unsuccessful, the cell is discarded, and the VPI_VCI_ERR counter at the
top of the hash table is incremented.
NOTE:
A bit bucket can be set up for cells with unknown VPI/VCIs. Instead of a
NULL NEXT pointer in the last hash bucket, a common connection can be
set up to handle these cells. By setting the AAL_TYPE to AAL0, a status
entry will be written for every cell with unknown VPI/VCI and the cell
will be written to a cell buffer.
Once a hash bucket match occurs, the VCC_PNTR is used to access the
RSM_VCC_TABLE. For AAL3/4, the pointer to the VCC table (VCC_PNTR) is
found from the result of the following calculation:
hash_bucket_base_address + 4 + (MID & (2
MID_BITS –1))
相關(guān)PDF資料 |
PDF描述 |
|---|---|
| 28L0138-40R | 1 FUNCTIONS, FERRITE BEAD |
| 28L0138-70R | 1 FUNCTIONS, FERRITE BEAD |
| 28Z551 | TELECOM FILTER |
| 28Z550 | TELECOM FILTER |
| 29103BRA | 16K X 1 STANDARD SRAM, 85 ns, CDIP20 |
相關(guān)代理商/技術(shù)參數(shù) |
參數(shù)描述 |
|---|---|
| 28230-18-01 | 功能描述:CORD 18AWG NEMA5-15P TO CABLE 制造商:orion fans 系列:- 零件狀態(tài):在售 樣式:公頭插針（刀片）到引線 第一連接器:NEMA 5-15P 第二連接器:線纜 導(dǎo)體數(shù):3 電線類型:SVT 線規(guī):18 AWG 屏蔽:無(wú)屏蔽 長(zhǎng)度:1.67'（508.0mm） 認(rèn)證標(biāo)記:已注冊(cè) ASTA、BSI Kitemark、CEBEC、CSA、DEMKO、ESTI、FIMKO、IMQ、KEMA、NF、NEMKO、OVE、SEMKO、SAA、T、UL、VDE 認(rèn)證國(guó)家/地區(qū):澳大利亞，加拿大，歐洲，芬蘭，日本，荷蘭，新西蘭，挪威，瑞典，英國(guó)，美國(guó) 顏色:黑色 額定電壓:125VAC 額定電流:10A 工作溫度:60°C 特性:- 標(biāo)準(zhǔn)包裝:1 |
| 282-302 | 制造商:WAGO Innovative Connections 功能描述:END PLATE, RAIL MOUNTED TERMINAL BLOCK; Series:-; Accessory Type:End Plate; For Use With:Rail Mounted Terminal Blocks ;RoHS Compliant: Yes |
| 282302-000 | 功能描述:CABLE 1 COND 12AWG SHIELDED RoHS:是 類別:線纜，導(dǎo)線 >> 單芯導(dǎo)線 系列:- 產(chǎn)品培訓(xùn)模塊:Basics of Wire and Cable 產(chǎn)品目錄繪圖:Stranded Hook Up Wire 標(biāo)準(zhǔn)包裝:1 系列:3070 纜線類型:電子線 線規(guī):24 AWG 線束:7/32 長(zhǎng)度:100' (30.5m) 套管類型:聚氯乙烯（PVC） 套管直徑:0.088"（2.24mm） 套管（絕緣體）厚度:0.032"（0.81mm） 電壓:600V 工作溫度:-20°C ~ 105°C 顏色:藍(lán) 特點(diǎn):UL 1015 型 線芯:1 其它名稱:3070 BK005 BLUEA3070L-100 |
| 282304-2 | 制造商:TE Connectivity 功能描述:AMP MODU II RCPT HSG - Bag |
| 28230-439-C | 制造商:Schroff/Pentair Electronic Packaging 功能描述: |
發(fā)布緊急采購(gòu)，3分鐘左右您將得到回復(fù)。