收藏本站
参数资料
型号： M7020R-050ZA1T
厂商： 意法半导体
英文描述： CAP TANT 22UF 10V 20% POLY SMD
中文描述： 32K的× 68位进入网络搜索引擎
文件页数： 47/150页
文件大小： 996K
代理商： M7020R-050ZA1T
47/150
M7020R
The following is the sequence of operation for a
single 68-bit SEARCH command (also refer to
Command Codes, page 29).
–
Cycle A:
The host ASIC drives the CMDV high
and applies SEARCH command code ('10') on
CMD[1:0] signals. CMD[5:3] signals must be
driven with the index to the GMR pair for use in
this SEARCH operation. CMD[8:7] signals must
be driven with the same bits that will be driven
on SADR[21:20] by this device if it has a hit.
DQ[67:0] must be driven with the 68-bit data to
be compared. The CMD[2] signal must be driv-
en to a logic '0.'
–
Cycle B:
The host ASIC continues to drive the
CMDV high and applies SEARCH command
('10') on CMD[1:0]. CMD[5:2] must be driven by
the index of the comparand register pair for stor-
ing the 136-bit word presented on the DQ Bus
during Cycles A and B. CMD[8:6] signals must
be driven with the index of the SSR that will be
used for storing the address of the matching en-
try and the Hit Flag (see SEARCH-Successful
Registers (SSR[0:7]), page 23). The DQ[67:0]
continues to carry the 68-bit data to be com-
pared.
Note:
For 68-bit searches, the host ASIC must
supply the same 68-bit data on DQ[67:0] during
both Cycles A and B. The even and odd pair of
GMRs selected for the comparison must be pro-
grammed with the same value.
The logical 68-bit SEARCH operation is shown in
Figure 29, page 50. The entire table (31 devices of
68-bit entries) is compared to a 68-bit word K (pre-
sented on the DQ Bus in both Cycles A and B of
the command) using the GMR and the local mask
bits. The effective GMR is the 68-bit word speci-
fied by the identical value in both even and odd
GMR pairs in each of the eight devices and select-
ed by the GMR Index in the command’s Cycle A.
The 68-bit word K (presented on the DQ Bus in
both Cycles A and B of the command) is also
stored in both even and odd comparand register
pairs in each of the eight devices and selected by
the Comparand Register Index in command’s Cy-
cle B. In the x68 configuration, the even com-
parand register can be subsequently used by the
LEARN command only in the first non-full device.
The word K (presented on the DQ Bus in both Cy-
cles A and B of the command) is compared with
each entry in the table starting at location “0.” The
first matching entry’s location address, “L,” is the
winning address that is driven as part of the SRAM
address on the SADR[21:0] lines (see SRAM AD-
DRESSING, page 126). The global winning device
will drive the bus in a specific cycle. On global miss
cycles the device with LRAM = 1 and LDEV = 1 will
be the default driver for such missed cycles.
The SEARCH command is a pipelined operation
and executes a search at half the rate of the fre-
quency of CLK2X for 68-bit searches in x68-con-
figured tables. The latency of SADR, CE_L,
ALE_L, WE_L, SSV, and SSF from the 68-bit
SEARCH command cycle (two CLK2X cycles) is
shown in Table 31, page 62.
For up to 31 devices in the table (TLSZ = 10),
search latency from command to SRAM access
cycle is 6. In addition, SSV and SSF shift further to
the right for different values of HLAT, as specified
in Table 32, page 62.
The 68-bit SEARCH operation is pipelined and ex-
ecutes as follows:
– Four cycles from the SEARCH command, each
of the devices knows the outcome internal to it
for that operation;
– In the fifth cycle after the SEARCH command,
the devices in a block arbitrate for a winner
amongst them (a “block” being defined as less
than or equal to eight devices resolving the win-
ner within them using the LHI[6:0] and LHO[1:0]
signalling mechanism);
– In the sixth cycle after the SEARCH command,
the blocks (of devices) resolve the winning block
through the BHI[2:0] and BHO[2:0] signalling
mechanism. The winning device within the win-
ning block is the global winning device for a
SEARCH operation.
Table 30. Hit/Miss Assumption
Search Number
1
2
3
4
Block 0
Miss
Miss
Miss
Miss
Block 1
Miss
Miss
Hit
Miss
Block 2
Miss
Hit
Hit
Miss
Block 3
Hit
Hit
Miss
Miss
相关PDF资料
PDF描述
M7020R-066ZA1T 32K x 68-bit Entry NETWORK SEARCH ENGINE
M7020R-083ZA1T 32K x 68-bit Entry NETWORK SEARCH ENGINE
M7020R 32K x 68-bit Entry NETWORK SEARCH ENGINE
M72DW64000B 64Mbit (x8/ x16, Multiple Bank, Boot Block) Flash Memory and 16Mbit Pseudo SRAM, 3V Supply, Multiple Memory Product
M72DW64000B70ZT 64Mbit (x8/ x16, Multiple Bank, Boot Block) Flash Memory and 16Mbit Pseudo SRAM, 3V Supply, Multiple Memory Product
相关代理商/技术参数
参数描述
M7020R-066ZA1T 制造商:STMICROELECTRONICS 制造商全称:STMicroelectronics 功能描述:32K x 68-bit Entry NETWORK SEARCH ENGINE
M7020R-083ZA1T 制造商:STMICROELECTRONICS 制造商全称:STMicroelectronics 功能描述:32K x 68-bit Entry NETWORK SEARCH ENGINE
M702-230442 功能描述:火线接头 IEEE 1394 SMT 4P HORIZONTAL RoHS:否 制造商:Molex 产品:IEEE 1394 Firewire Connectors 标准:IEEE 1394 位置/触点数量:6 节距:2 mm 触点电镀:Unplated 触点材料:Phosphor Bronze 型式:Female 电流额定值:0.5 A 安装风格:Through Hole 端接类型:Solder Tab 连接器类型:Firewire Receptacle
M702-230642 功能描述:火线接头 IEEE 1394 SMT 6P HORIZONTAL RoHS:否 制造商:Molex 产品:IEEE 1394 Firewire Connectors 标准:IEEE 1394 位置/触点数量:6 节距:2 mm 触点电镀:Unplated 触点材料:Phosphor Bronze 型式:Female 电流额定值:0.5 A 安装风格:Through Hole 端接类型:Solder Tab 连接器类型:Firewire Receptacle
M7023 制造商:Tamura Corporation of America 功能描述:
发布紧急采购，3分钟左右您将得到回复。

采购需求

(若只采购一条型号，填写一行即可)

发布成功！您可以继续发布采购。也可以进入我的后台，查看报价

发布成功！您可以继续发布采购。也可以进入我的后台，查看报价

*型号 *数量 厂商 批号 封装
添加更多采购

我的联系方式

*
*
*