参数资料
型号: DS31256+
厂商: Maxim Integrated Products
文件页数: 173/183页
文件大小: 0K
描述: IC CTRLR HDLC 256-CHANNEL 256BGA
产品培训模块: Lead (SnPb) Finish for COTS
Obsolescence Mitigation Program
标准包装: 40
控制器类型: HDLC 控制器
接口: 串行
电源电压: 3 V ~ 3.6 V
电流 - 电源: 500mA
工作温度: 0°C ~ 70°C
安装类型: 表面贴装
封装/外壳: 256-BBGA
供应商设备封装: 256-BGA(27x27)
包装: 管件
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DS31256 256-Channel, High-Throughput HDLC Controller
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which are called “large” and “small” but that can be set to any size up to 8188 bytes. The user has the
option to store the incoming data either, only in the large buffers, only in the small buffers, or fill a small
buffer first and then fill large buffers as needed. The varying buffer storage options allow the user to
make the best use of the available memory and to be able to balance the tradeoff between latency and bus
utilization.
The DMA uses a set of descriptors to know where to store the incoming HDLC packet data and where to
obtain HDLC packet data that is ready to be transmitted. The descriptors are fixed size messages that are
handed back and forth from the DMA to the host. Since this descriptor transfer utilizes bus cycles, the
DMA has been structured to minimize the number of transfers required. For example on the receive side,
the DMA obtains descriptors from the host to know where in the 32-bit address space to place the
incoming packet data. These descriptors are known as free-queue descriptors. When the DMA reads
these descriptors off of the PCI Bus, they contain all the information that the DMA needs to know where
to store the incoming data. Unlike other existing scatter/gather DMA architectures, the DS31256 DMA
does not need to use any more bus cycles to determine where to place the data. Other DMA architectures
tend to use pointers, which require them to go back onto the bus to obtain more information and hence
use more bus cycles.
Another technique that the DMA uses to maximize bus utilization is the ability to burst read and write
the descriptors. The device can be enabled to read and write the descriptors in bursts of 8 or 16 instead of
one at a time. Since there is fixed overhead associated with each bus transaction, the ability to burst read
and write descriptors allows the device to share the bus overhead among 8 or 16 descriptor transactions
which reduces the total number of bus cycles needed.
The DMA can also burst up to 256 dwords (1024 bytes) onto the PCI Bus. This helps to minimize bus
cycles by allowing the device to burst large amounts of data in a smaller number of bus transactions that
reduces bus cycles by reducing the amount of fixed overhead that is placed on the bus.
The Local Bus block has two modes of operation. It can be used as either a bridge from the PCI Bus in
which case it is a bus master or it can be used as a configuration bus in which case it is a bus slave. The
bridge mode allows the host on the PCI Bus to access the local bus. The DS31256 maps data from the
PCI Bus to the local bus. In the configuration mode, the local bus is used only to control and monitor the
DS31256 while the HDLC packet data will still be transferred to the host through the PCI Bus.
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相关代理商/技术参数
参数描述
DS31256+ 功能描述:输入/输出控制器接口集成电路 256Ch High Thruput HDLC Cntlr RoHS:否 制造商:Silicon Labs 产品: 输入/输出端数量: 工作电源电压: 最大工作温度:+ 85 C 最小工作温度:- 40 C 安装风格:SMD/SMT 封装 / 箱体:QFN-64 封装:Tray
DS31256B 功能描述:输入/输出控制器接口集成电路 256Ch High Thruput HDLC Cntlr RoHS:否 制造商:Silicon Labs 产品: 输入/输出端数量: 工作电源电压: 最大工作温度:+ 85 C 最小工作温度:- 40 C 安装风格:SMD/SMT 封装 / 箱体:QFN-64 封装:Tray
DS31256DK 功能描述:网络开发工具 RoHS:否 制造商:Rabbit Semiconductor 产品:Development Kits 类型:Ethernet to Wi-Fi Bridges 工具用于评估:RCM6600W 数据速率:20 Mbps, 40 Mbps 接口类型:802.11 b/g, Ethernet 工作电源电压:3.3 V
DS31256-W+ 制造商:Maxim Integrated Products 功能描述:ENVOY 256 CHANNEL HDLC - WAIVER - Rail/Tube
DS312BNC 制造商:未知厂家 制造商全称:未知厂家 功能描述:Industrial Control IC