参数资料
| 型号： | KSZ8842-16MBLI TR |
| 厂商： | Micrel Inc |
| 文件页数： | 72/141页 |
| 文件大小： | 0K |
| 描述： | IC ETHERNET SW 2PORT 100LFBGA |
| 标准包装： | 1,000 |
| 控制器类型： | 以太网开关控制器 |
| 接口： | PCI |
| 电源电压： | 3.1 V ~ 3.5 V |
| 工作温度： | -40°C ~ 85°C |
| 安装类型： | 表面贴装 |
| 封装/外壳： | 100-LBGA |
| 供应商设备封装： | 100-LFBGA |
| 包装： | 带卷 (TR) |
第1页第2页第3页第4页第5页第6页第7页第8页第9页第10页第11页第12页第13页第14页第15页第16页第17页第18页第19页第20页第21页第22页第23页第24页第25页第26页第27页第28页第29页第30页第31页第32页第33页第34页第35页第36页第37页第38页第39页第40页第41页第42页第43页第44页第45页第46页第47页第48页第49页第50页第51页第52页第53页第54页第55页第56页第57页第58页第59页第60页第61页第62页第63页第64页第65页第66页第67页第68页第69页第70页第71页当前第72页第73页第74页第75页第76页第77页第78页第79页第80页第81页第82页第83页第84页第85页第86页第87页第88页第89页第90页第91页第92页第93页第94页第95页第96页第97页第98页第99页第100页第101页第102页第103页第104页第105页第106页第107页第108页第109页第110页第111页第112页第113页第114页第115页第116页第117页第118页第119页第120页第121页第122页第123页第124页第125页第126页第127页第128页第129页第130页第131页第132页第133页第134页第135页第136页第137页第138页第139页第140页第141页
Micrel, Inc.
KSZ8842-16/32 MQL/MVL/MVLI/MBL
October 2007
36
M9999-102207-1.9
To avoid jabber and excessive deference (as defined in the 802.3 standard), after a certain time, the KSZ8842M
discontinues the carrier sense and then raises it again quickly. This short silent time (no carrier sense) prevents other
stations from sending out packets thus keeping other stations in a carrier sense deferred state. If the port has packets to
send during a backpressure situation, the carrier sense type backpressure is interrupted and those packets are
transmitted instead. If there are no additional packets to send, carrier sense type backpressure is reactivated again until
switch resources free up. If a collision occurs, the binary exponential back-off algorithm is skipped and carrier sense is
generated immediately, thus reducing the chance of further collisions and carrier sense is maintained to prevent packet
reception.
To ensure no packet loss in 10 BASE-T or 100 BASE-TX half-duplex modes, the user must enable the following:
1.
Aggressive back off (bit 8 in SGCR1)
2.
No excessive collision drop (bit 3 in SGCR2)
Note: These bits are not set in default, since this is not the IEEE standard.
Broadcast Storm Protection
The KSZ8842M has an intelligent option to protect the switch system from receiving too many broadcast packets. As the
broadcast packets are forwarded to all ports except the source port, an excessive number of switch resources (bandwidth
and available space in transmit queues) may be utilized. The KSZ8842M has the option to include “multicast packets” for
storm control. The broadcast storm rate parameters are programmed globally, and can be enabled or disabled on a per
port basis in P1CR1[7] and P2CR1[7]. The rate is based on a 67ms interval for 100BT and a 670ms interval for 10BT. At
the beginning of each interval, the counter is cleared to zero and the rate limit mechanism starts to count the number of
bytes during the interval. The rate definition is described in SGCR3[2:0][15:8]. The default setting is 0x63 (99 decimal).
This is equal to a rate of 1%, calculated as follows:
148,800 frames/sec X 67 ms/interval X 1% = 99 frames/interval (approx.) = 0x63
Note: 148,800 frames/sec is based on 64-byte block of packets in 100BASE-T with 12 bytes of IPG and 8 bytes of
preamble between two packets.
Repeater Mode
When the KSZ8842M is set to repeater mode (SGCR3[7] = 1), it only works on 100BT half-duplex mode. In repeater
enabled mode, all ingress packets will be broadcast to the other two ports without MAC address checking and learning.
Before setting to the repeater mode, the user has to set bit 13 (100Mbps), bit 12 (auto-negotiation disabled) and bit 8 (half
duplex) in both P1MBCR and P2MBCR registers as well as set bit 6 (host half duplex) in SGCR3 register for the repeater
mode.
The latency in repeater mode is defined from the 1st bit of DA into the ingress port 1 to the 1st bit of DA out of the egress
port 2. The minimum is 270 ns and the maximum is 310 ns (one clock skew of 25 MHz between TX and RX).
Clock Generator
The X1 and X2 pins are connected to a 25 MHz crystal. X1 can also serve as the connector to a 3.3V, 25 MHz oscillator
(as described in the pin description).
The bus interface unit (BIU) uses BCLK (Bus Clock) for synchronous accesses. The maximum host port frequency is 50
MHz for VLBus-like and burst mode (32-bit interface only).
Bus Interface Unit (BIU)
The host interface of the BIU is designed to communicate with embedded processors. The host interface of the
KSZ8842M is a generic bus interface. Some glue logic may be required when the interface talks to various buses and
processors.
In terms of transfer type, the BIU can support two transfers: asynchronous transfer and synchronous transfer. To support
these transfers (asynchronous and synchronous), the BIU provides three groups of signals:
1.
Synchronous signals
2.
Asynchronous signals
3.
Common signals are used for both synchronous and asynchronous transfers.
Since both synchronous and asynchronous signals are independent of each other, synchronous burst transfer and
asynchronous transfer can be mixed or interleaved but cannot be overlapped (due to the sharing of the common signals).
In terms of physical data bus size, the KSZ8842M supports 8, 16, and 32 bit host/industrial standard data bus sizes.
Given a physical data bus size, the KSZ8842M supports 8, 16, or 32-bit data transfers depending on the size of the
相关PDF资料 |
PDF描述 |
|---|---|
| KSZ8842-32MVLI | IC SWITCH ETH 2P 32BIT 128LQFP |
| KSZ8842-PMBL AM TR | IC ETHERNET SW 2PORT 100LFBGA |
| KSZ8842-PMQLI | IC ETHERNET SW 2PORT PCI 128PQFP |
| KSZ8851-16MLLI TR | IC MAC CTLR 1PORT W/BUS 48LQFP |
| KSZ8851-16MLLJ | IC CTLR MAC 1PORT NON-PCI 48LQFP |
相关代理商/技术参数 |
参数描述 |
|---|---|
| KSZ8842-16MQL | 功能描述:以太网 IC 2-Port Ethernet Switch/Repeater + Generic (8, 16-bit) bus interface(Lead Free) RoHS:否 制造商:Micrel 产品:Ethernet Switches 收发器数量:2 数据速率:10 Mb/s, 100 Mb/s 电源电压-最大:1.25 V, 3.45 V 电源电压-最小:1.15 V, 3.15 V 最大工作温度:+ 85 C 封装 / 箱体:QFN-64 封装:Tray |
| KSZ8842-16MQL-EVAL | 功能描述:以太网开发工具 KSZ8842-16MQL Evaluation Board RoHS:否 制造商:Micrel 产品:Evaluation Boards 类型:Ethernet Transceivers 工具用于评估:KSZ8873RLL 接口类型:RMII 工作电源电压: |
| KSZ8842-16MVL | 功能描述:以太网 IC 2-Port Ethernet Switch/Repeater + Generic (8, 16-bit) bus interface(Lead Free) RoHS:否 制造商:Micrel 产品:Ethernet Switches 收发器数量:2 数据速率:10 Mb/s, 100 Mb/s 电源电压-最大:1.25 V, 3.45 V 电源电压-最小:1.15 V, 3.15 V 最大工作温度:+ 85 C 封装 / 箱体:QFN-64 封装:Tray |
| KSZ8842-16MVL TR | 功能描述:以太网 IC 2-Port Ethernet Switch/Repeater + Generic (8, 16-bit) bus interface(Lead Free) RoHS:否 制造商:Micrel 产品:Ethernet Switches 收发器数量:2 数据速率:10 Mb/s, 100 Mb/s 电源电压-最大:1.25 V, 3.45 V 电源电压-最小:1.15 V, 3.15 V 最大工作温度:+ 85 C 封装 / 箱体:QFN-64 封装:Tray |
| KSZ8842-16MVL-EVAL | 功能描述:BOARD EVALUATION KSZ8842-16MVL RoHS:是 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 |
发布紧急采购，3分钟左右您将得到回复。