瑞士Bitmine系列报道之三：CoinCraft矿机28nmA1芯片简介

彩云比特lvl翻译

    Coincraft A1芯片由Bitmine公司全新设计，Coincraft A1矿机是Bitmine公司第三代比特币挖矿设备，由Bitmine和Innosilicon联合研发，致力于达到最佳的功耗性能，A1矿机的构造适合于私人或大规模公司矿厂部署。

    在2013年11月最后一个星期将可以开始批量生产，A1采用GlobalFoundries尖端的28nmHPP 和超低电压的晶体管技术以及客户全定制封装，未来我们的设备将拥有自主设计的电源模式以达到超低电压和高算力，然后你是想要低功耗还是高算力，A1芯片都可以完美的满足你。

    我们的ASIC芯片设计已经耗时半年以上，并不断分析现在的比特币挖矿行业和未来的行业趋势。基于这些研究我们认为我们的ASIC比特币矿机芯片将是业内最好的28nm比特币矿机ASIC芯片。

CoinCraft A1 ASIC芯片特点：

 
1、采用GlobalFoundries28nm HPP技术

2、客户全定制封装技术、独特的电源设计达到低功耗，高算力

3、甚至可以4095片芯片级联

4、标准的I2C接口

5、正常模式20GH/S，高速率模式达40GH/S

6、在低功耗模式时为0.35W/GH 正常模式0.6W/G 高速率模式1W/G

7、低功耗模式电压为0.5V，正常模式电压为0.65V，高速率模式为0.75V

8、在2013年11月最后一个星期将开始批量生产

请注意：虽然我们采取了尽可能高准确率的和保守的模拟，最终产品性能可能会有所不同，可能会有+/ - 20％的偏差。

高算力不是最好的选择：

    你是否认为让你的芯片跑到每个单位达500GH/S的算力是最好的选择？根据经验我们并不这样认为，我们的目标是最低的系统总成本和最大的可扩展性，实现由小而酷的ASIC的芯片大型阵列，我们之所以称A1被设计得如此完美，就是他可以满足小型和非常大的公营或私营采矿厂的部署

行业领先的功耗比：

    我们的芯片设计功耗将低于0.35W/GH在低耗电模式，我们这样的功耗比将是业内绝对领先，应此我们的设备将是最具有盈利潜力的比特币挖矿设备。我们拥有顶级设计专家和IC工程师SHA256工作引擎的独家授权。

标准的12C接口协议：

   我们在系统设计中要求尽量达最少的外部元件，这是一个CoinCraft A1了不起的特点。我们通过采用行业标准的I2C接口协议，可以促进一个庞大的代工产业以及廉价的成本，减少进入市场的时间和总BOM成本

树形或构菊花链编程结构均可使用：

       更大规模的设计方案工作效能很可能会由于每一新的比特币作业所需传播时间而受阻。每一新的比特币作业需经过芯片的菊花链直到最后的IC，因此而会浪费几百个甚至几千个周期，A1芯片解決此难题的全新方案基于使用二进制树形结构，每一芯片将作业传播给树中的两个子节点，因而将511个IC树形结构作业传播时间降至8个时钟周期！A1芯片也可以设置成传统的菊花链编程结构，以用于较小的的阵列，或根据简易设计的需要。

客户全定制电源IC封装：

    我们目前这一代ASIC设计的一个重要瓶颈就是是高电流的集成电路限制。有些人试图通过使用大量的BGA引脚解决这个问题，但这样的设计会使得最终芯片封装更大，更昂贵，可能导致热偏移引起开裂危险。我们已经解决了这个问题，通过采用定制的封装，而不是引脚封装，使得电源能够提供充沛的供应，同时保持小封装尺寸和满足Bitcoin的挖掘涉及的高功耗。

转自：http://www.cybtc.com/portal.php?mod=view&aid=137
原文：

Designed from scratch, Bitmine’s Coincraft A1 is a third generation Bitcoin Mining IC developed by Bitmine in co-operation with a team of expert engineers from Innosilicon. Targeting the highest possible power efficiency, the A1 is made to be deployed in huge binary trees structures within large scale private or public mining pools.

Available in mass scale production starting from the last week of November 2013, the A1 employs cutting edge 28nm HPP technology from GlobalFoundries and ultra low voltage transistors, packaged into a custom engineered IC package that features our proprietary PowerBar technology for very low voltage, high current applications. Whether you want low power usage or high performances, the A1 fits perfectly both.

Our ASIC is the result of more than half a year of engineering and analysis of current systems limitations and predicted future of Bitcoin mining. That’s why we are confident it will be the best ASIC Bitcoin Miner design ever to be available on 28nm technology.

Technical specifications* of the CoinCraft A1 ASIC:

Developed on 28nm HPP process from Global Foundries
Custom IC package with power bars for low voltage, high current feeding
Configurable in binary tree or daisy chain mode for distributed work with up to 4095 ASICs.
Standard I2C interface
Hashing power of 20 GH/s in nominal and 40 GH/s in Turbo mode
Power usage of 0.35 W/GH in low power, 0.6 W/GH in nominal and 1 W/GH in Turbo mode
Supply voltage of 0.5V in low power, 0.65 V in nominal and 0.75 V in Turbo mode
Mass production available starting from the last week of November 2013
* Please note that while we took the highest possible care in doing accurate and conservative simulations, the real performances of the final product could vary by a +/- 20% tolerance

Bigger isn’t better.

Do you think that fitting the highest possible number of hashing units into a single, 500+ GH/s silicon die is the best solution? We don’t. Real life experience has shown that the highest performance, lowest total system cost and greatest scalability are achieved by large arrays of small and cool ASICs. That’s the reason why the A1 was designed so perfectly and was thought from the ground up to scale to very large private or public mining pools.

Power horse or cool chip?

You choose. Lower power usage means also greater overclocking abilities, the CoinCraft A1 design allows for supply voltages as low as 0.5V for extremely low power, high efficiency designs. But when you need to squeeze out the highest possible amount of power, the A1 has no rivals. Thanks to its PowerTune feature, the A1 can  run at twice the nominal speed in Turbo mode, or even further if adequate power dissipation is given. Run your systems in Turbo mode to get the highest possible profits when the difficulty is low and switch them at a later time to low power mode to reduce energy consumption and operating cost when needed.

Industry leading power efficiency

With power usage ratios as low as 0.35 W/GH in ultra low power mode, our design clearly marks the top of the Industry in terms of power efficiency and, as such, delivers the highest profitability out of all Bitcoin mining devices. This was achieved both by dedicating a significant number of top-level experts and IC engineers to the system’s design and by the exclusive licensing of highly optimized, patented SHA256 work engines

Standard I2C interfacing protocol

Keeping the system’s total external components to a minimum is one of the great accomplishments of CoinCraft A1. By adopting the industry standard I2C protocol, a huge and powerful tree of IC can interface itself to hosts that are as small and inexpensive as a low cost PIC from Microchip, reducing the time to market and total BOM costs dramatically.

Tree or daisy chain configuration ready

Larger scale designs can see their performances degraded by the propagation time needed for a new Bitcoin job to walk through the daisy chain of chips till the last IC, wasting hundreds or even thousands of clock cycles. The A1 addresses this issue in a completely new way by using a binary tree structure where each chip propagates the work to two children nodes in the tree, reducing the propagation time to just 8 clock cycles for a tree of 511 ICs! The A1 can also be configured to work in the traditional daisy chain mode where smaller arrays or simpler design is required.

Customized high power IC package

One of the practical limits of current generation ASIC designs is the high supply current that the IC requires. Some have tried to work around this problem by using a huge amount of BGA pins, but this design makes the final package bigger, more expensive and subject to dangerous thermal excursions of the package that could lead to crackings. We have solved the problem by adopting a custom package that uses bars instead of pins for the power supply, giving plenty of energy to the IC while keeping the package size small and resistant to the high power dissipation figures involved in Bitcoin mining.