参数资料
型号: KS8993M
厂商: Micrel Inc
文件页数: 19/85页
文件大小: 0K
描述: IC SWITCH 10/100 3PORT 128PQFP
标准包装: 66
系列: *
类型: *
应用: *
安装类型: 表面贴装
封装/外壳: 128-BFQFP
供应商设备封装: 128-PQFP(14x20)
包装: 管件
配用: 576-1013-ND - BOARD EVAL EXPERIMENT KS8993M
Micrel, Inc.
KS8993M/ML/MI
April 2005
26
M9999-041205
Functional Overview: MAC and Switch
Address Lookup
The internal lookup table stores MAC addresses and their associated information. It contains a 1K uni-cast
address table plus switching information. The KS8993M is guaranteed to learn 1K addresses and distinguishes
itself from hash-based lookup tables, which depending on the operating environment and probabilities, may not
guarantee the absolute number of addresses that can be learned.
Learning
The internal lookup engine will update its table with a new entry if the following conditions are met:
1.
The received packet's SA does not exist in the lookup table.
2.
The received packet is good; the packet has no receiving errors, and is of legal length.
The lookup engine will insert the qualified SA into the table, along with the port number and time stamp. If the
table is full, the last entry of the table will be deleted to make room for the new entry.
Migration
The internal lookup engine also monitors whether a station has moved. If so, it will update the table accordingly.
Migration happens when the following conditions are met:
1.
The received packet's SA is in the table but the associated source port information is different.
2.
The received packet is good; the packet has no receiving errors, and is of legal length.
The lookup engine will update the existing record in the table with the new source port information.
Aging
The lookup engine will update the time stamp information of a record whenever the corresponding SA appears.
The time stamp is used in the aging process. If a record is not updated for a period of time, the lookup engine will
remove the record from the table. The lookup engine constantly performs the aging process and will continuously
remove aging records. The aging period is about 200 seconds. This feature can be enabled or disabled through
Global Register 3 (0x03).
Forwarding
The KS8993M will forward packets using the algorithm that is depicted in the following flowcharts. Figure 4 shows
stage one of the forwarding algorithm where the search engine looks up the VLAN ID, static table, and dynamic
table for the destination address, and comes up with “port to forward 1” (PTF1). PTF1 is then further modified by
spanning tree, IGMP snooping, port mirroring, and port VLA processes to come up with “port to forward 2”
(PTF2), as shown in Figure 5. The packet is sent to PTF2.
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KS8993M_11 制造商:MICREL 制造商全称:Micrel Semiconductor 功能描述:Integrated 3-Port 10/100 Managed Switch with PHYs
KS8993MA5 功能描述:IC SWITCH 3-PORT 10/100 128-PQFP RoHS:否 类别:集成电路 (IC) >> 专用 IC 系列:* 产品培训模块:Lead (SnPb) Finish for COTS Obsolescence Mitigation Program 标准包装:1 系列:- 类型:调帧器 应用:数据传输 安装类型:表面贴装 封装/外壳:400-BBGA 供应商设备封装:400-PBGA(27x27) 包装:散装
KS8993M-EVAL 功能描述:BOARD EVAL EXPERIMENT KS8993M RoHS:否 类别:编程器,开发系统 >> 评估演示板和套件 系列:- 产品培训模块:Obsolescence Mitigation Program 标准包装:1 系列:- 主要目的:电源管理,电池充电器 嵌入式:否 已用 IC / 零件:MAX8903A 主要属性:1 芯锂离子电池 次要属性:状态 LED 已供物品:板
KS8993MI 功能描述:IC SWITCH 10/100 3PORT 128PQFP RoHS:否 类别:集成电路 (IC) >> 专用 IC 系列:* 产品培训模块:Lead (SnPb) Finish for COTS Obsolescence Mitigation Program 标准包装:1 系列:- 类型:调帧器 应用:数据传输 安装类型:表面贴装 封装/外壳:400-BBGA 供应商设备封装:400-PBGA(27x27) 包装:散装
KS8993ML 功能描述:IC SWITCH 10/100 3PORT 128PQFP RoHS:否 类别:集成电路 (IC) >> 专用 IC 系列:* 产品培训模块:Lead (SnPb) Finish for COTS Obsolescence Mitigation Program 标准包装:1 系列:- 类型:调帧器 应用:数据传输 安装类型:表面贴装 封装/外壳:400-BBGA 供应商设备封装:400-PBGA(27x27) 包装:散装