- 您現(xiàn)在的位置：買賣IC網(wǎng) > PDF目錄1931 > KS8995XA (Micrel Inc)IC SWITCH 10/100 5PORT 128PQFP PDF資料下載
參數(shù)資料
| 型號： | KS8995XA |
| 廠商： | Micrel Inc |
| 文件頁數(shù)： | 15/51頁 |
| 文件大?。?/td> | 0K |
| 描述： | IC SWITCH 10/100 5PORT 128PQFP |
| 標(biāo)準(zhǔn)包裝： | 66 |
| 系列： | * |
| 類型： | * |
| 應(yīng)用： | * |
| 安裝類型： | 表面貼裝 |
| 封裝/外殼： | 128-BFQFP |
| 供應(yīng)商設(shè)備封裝： | 128-PQFP（14x20） |
| 包裝： | 散裝 |
| 配用： | 576-1604-ND - EVAL KIT EXPERIMENTAL KS8995XA |
第1頁第2頁第3頁第4頁第5頁第6頁第7頁第8頁第9頁第10頁第11頁第12頁第13頁第14頁當(dāng)前第15頁第16頁第17頁第18頁第19頁第20頁第21頁第22頁第23頁第24頁第25頁第26頁第27頁第28頁第29頁第30頁第31頁第32頁第33頁第34頁第35頁第36頁第37頁第38頁第39頁第40頁第41頁第42頁第43頁第44頁第45頁第46頁第47頁第48頁第49頁第50頁第51頁
KS8995XA
Micrel, Inc.
M9999-051305
22
May 2005
Media Access Controller (MAC) Operation
The KS8995XA strictly abides by IEEE 802.3 standards to maximize compatibility.
Inter-Packet Gap (IPG)
If a frame is successfully transmitted, the 96-bit time IPG is measured between the two consecutive MTXEN. If the current
packet is experiencing collision, the 96-bit time IPG is measured from MCRS and the next MTXEN.
Backoff Algorithm
The KS8995XA implements the IEEE Std. 802.3 binary exponential back-off algorithm, and optional “aggressive mode” back
off. After 16 collisions, the packet will be optionally dropped depending on the chip configuration in Register 3. See “Register
3.”
Late Collision
If a transmit packet experiences collisions after 512-bit times of the transmission, the packet will be dropped.
Illegal Frames
The KS8995XA discards frames less than 64 bytes and can be programmed to accept frames up to 1536 bytes in Register
4. For special applications, the KS8995XA can also be programmed to accept frames up to 1916 bytes in Register 4. Since
the KS8995XA supports VLAN tags, the maximum sizing is adjusted when these tags are present.
Flow Control
The KS8995XA supports standard 802.3x flow control frames on both transmit and receive sides.
On the receive side, if the KS8995XA receives a pause control frame, the KS8995XA will not transmit the next normal frame
until the timer, specified in the pause control frame, expires. If another pause frame is received before the current timer expires,
the timer will be updated with the new value in the second pause frame. During this period (being flow controlled), only flow
control packets from the KS8995XA will be transmitted.
On the transmit side, the KS8995XA has intelligent and efficient ways to determine when to invoke flow control. The flow control
is based on availability of the system resources, including available buffers, available transmit queues and available receive
queues.
The KS8995XA will flow control a port, which just received a packet, if the destination port resource is being used up. The
KS8995XA will issue a flow control frame (XOFF), containing the maximum pause time defined in IEEE standard 802.3x. Once
the resource is freed up, the KS8995XA will send out the other flow control frame (XON) with zero pause time to turn off the
flow control (turn on transmission to the port). A hysteresis feature is provided to prevent the flow control mechanism from being
activated and deactivated too many times.
The KS8995XA will flow control all ports if the receive queue becomes full.
Half-Duplex Back Pressure
A half-duplex back pressure option (note: not in 802.3 standards) is also provided. The activation and deactivation conditions
are the same as the above in full-duplex mode. If back pressure is required, the KS8995XA will send preambles to defer the
other stations’ transmission (carrier sense deference). To avoid jabber and excessive deference defined in 802.3 standard,
after a certain time it will discontinue the carrier sense but it will raise the carrier sense quickly. This short silent time (no carrier
sense) is to prevent other stations from sending out packets and keeps other stations in carrier sense deferred state. If the port
has packets to send during a back pressure situation, the carrier-sense-type back pressure will be interrupted and those
packets will be transmitted instead. If there are no more packets to send, carrier-sense-type back pressure will be active again
until switch resources are free. If a collision occurs, the binary exponential back-off algorithm is skipped and carrier sense is
generated immediately, reducing the chance of further colliding and maintaining carrier sense to prevent reception of packets.
To ensure no packet loss in 10BASE-T or 100BASE-TX half-duplex modes, the user must enable the following:
Aggressive backoff (register 3, bit 0)
No excessive collision drop (register 4, bit 3)
Back pressure (register 4, bit 5)
These bits are not set as the default because this is not the IEEE standard.
相關(guān)PDF資料 |
PDF描述 |
|---|---|
| KS8997 | IC SWITCH 10/100 8PORT 128PQFP |
| KS8999I | IC SWITCH 9-PORT 10/100 208-PQFP |
| KSZ8001LI TR | IC TXRX PHY 10/100 3.3V 48LQFP |
| KSZ8031RNLI | TXRX PHY 10/100 3.3V 24-QFN |
| KSZ8041MLL TR | TXRX 10/100 3.3V PHY MII 48LQFP |
相關(guān)代理商/技術(shù)參數(shù) |
參數(shù)描述 |
|---|---|
| KS8995XA_11 | 制造商:MICREL 制造商全稱:Micrel Semiconductor 功能描述:Integrated 5-Port 10/100 QoS Switch |
| KS8995XA4 | 功能描述:IC SWITCH 5-PORT 10/100 128-PQFP RoHS:否 類別:集成電路 (IC) >> 專用 IC 系列:* 產(chǎn)品培訓(xùn)模塊:Lead (SnPb) Finish for COTS Obsolescence Mitigation Program 標(biāo)準(zhǔn)包裝:1 系列:- 類型:調(diào)幀器 應(yīng)用:數(shù)據(jù)傳輸 安裝類型:表面貼裝 封裝/外殼:400-BBGA 供應(yīng)商設(shè)備封裝:400-PBGA（27x27） 包裝:散裝 |
| KS8995XAB3 | 功能描述:IC SWITCH 5-PORT 10/100 128-PQFP RoHS:否 類別:集成電路 (IC) >> 專用 IC 系列:* 產(chǎn)品培訓(xùn)模塊:Lead (SnPb) Finish for COTS Obsolescence Mitigation Program 標(biāo)準(zhǔn)包裝:1 系列:- 類型:調(diào)幀器 應(yīng)用:數(shù)據(jù)傳輸 安裝類型:表面貼裝 封裝/外殼:400-BBGA 供應(yīng)商設(shè)備封裝:400-PBGA（27x27） 包裝:散裝 |
| KS8995XA-EVAL | 功能描述:EVAL KIT EXPERIMENTAL KS8995XA RoHS:是 類別:編程器，開發(fā)系統(tǒng) >> 評估演示板和套件 系列:- 產(chǎn)品培訓(xùn)模塊:Obsolescence Mitigation Program 標(biāo)準(zhǔn)包裝:1 系列:- 主要目的:電源管理，電池充電器 嵌入式:否 已用 IC / 零件:MAX8903A 主要屬性:1 芯鋰離子電池 次要屬性:狀態(tài) LED 已供物品:板 |
| KS8995XC | 制造商:RF Micro Devices Inc 功能描述: |
發(fā)布緊急采購，3分鐘左右您將得到回復(fù)。