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參數(shù)資料
| 型號： | RTL8308B |
| 廠商： | Electronic Theatre Controls, Inc. |
| 英文描述： | REALTEK SINGLE CHIP 8-PORT 10/100 ETHERNET SWITCH CONTROLLER WITH EMBEDDED MEMORY |
| 中文描述： | 瑞昱單片8端口10/100以太網(wǎng)交換機(jī)控制器，嵌入式存儲器 |
| 文件頁數(shù)： | 15/28頁 |
| 文件大?。?/td> | 397K |
| 代理商： | RTL8308B |
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RTL8308B
2002/01/23
Rev. 2.0
15
If the Spanning Tree Protocol is enabled, the RTL8308B will forward the packet as follows:
1. If the port is in the Block-N-Listen state or the Learning state, forward the packet to the CPU when it is a BPDU
packet, discard the packet otherwise;
2. If the port is in the Forwarding State, forward the packet to the CPU when it is a BPDU packet.
6.10 Back off Algorithm
The RTL8308B implements the truncated exponential back off algorithm compliant to the IEEE 802.3 standard.
The collision counter will be restarted after 16 consecutive collisions.
6.11 Inter-Frame Gap
The Inter-Frame Gap is 9.6us for 10Mbps Ethernet and is 960ns for 100Mbps fast Ethernet.
6.12 Buffer Management
An embedded 2M bit (32K x 64 ) or 256K byte DRAM operating at the 50MHz clock rate is built-in as a packet
storage buffer. To efficiently utilize the packet buffer, the RTL8308B divides the 2Mbit (256Kbytes) DRAM into
1K pages of storage space, i.e., each page contains 256 bytes. For Ethernet packets, a maximum of seven pages can
be used and the minimum is one.
The embedded DRAM is divided into two parts. The first is the Packet Buffer Space, used for storing received
packet data. The second is Page Pointer Space for buffer management. The Packet Buffer Space consists of about
1k storage units in a page. Each page consists of 8-byte Header information, including next page pointer and
received byte count, and 248 bytes of data. The page pointers are contained in Page Pointer Space.
Packet Buffer Space
(about 1K pages)
Page Pointer Space
6.13 Buffer Manager
2M bit DRAM
The Buffer Manager of the RTL8308B contains a Free Page Pointer FIFO pool to store and provide available free
page pointers to all ports. After power up reset, the Buffer Manager will initiate the
Descriptor Read
command to
get some available free page pointers from Page Pointer Space. When the contents of the Free Page Pointer FIFO is
almost empty due to continuous data receptions, the Descriptor Read command will be reinitiated to get more
available free page pointers. However, when the FIFO contents are almost full due to continuous successful data
transmissions, the RTL8308B initiates the
Descriptor Write
command to write the additional available free page
pointers back to Page Pointers Space.
相關(guān)PDF資料 |
PDF描述 |
|---|---|
| RTL8309SB | SINGLE-CHIP 9-PORT 10/100MBPS SWITCH CONTROLLER |
| RTS0072 | VOICE CHANGER |
| RTS0072B | VOICE CHANGER |
| RU4D | SDR Cable Assembly; Connector Type A:micro D Ribbon Plug; Connector Type B:micro D Ribbon Plug; Cable Length:2m; No. of Contacts:26; Pitch Spacing:0.8mm RoHS Compliant: Yes |
| RU4D | Damper Diodes (For Display) |
相關(guān)代理商/技術(shù)參數(shù) |
參數(shù)描述 |
|---|---|
| RTL8309SB | 制造商:未知廠家 制造商全稱:未知廠家 功能描述:SINGLE-CHIP 9-PORT 10/100MBPS SWITCH CONTROLLER |
| RTL8309SB-LF | 制造商:Realtek Semiconductor 功能描述:RTL8309 Series 9 Port 10/100 Mbps Ethernet Switch Controller - PQFP-128 制造商:Realtek 功能描述:RTL8309 Series 9 Port 10/100 Mbps Ethernet Switch Controller - PQFP-128 |
| RTL8316 | 制造商:未知廠家 制造商全稱:未知廠家 功能描述:Specifications |
| RTL8363S-GR | 制造商:Realtek Semiconductor 功能描述: |
| RTL8801 | 制造商:未知廠家 制造商全稱:未知廠家 功能描述:Specifications |
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