Remotely Performing IC Validation

Remotely Performing IC Validation

设计任何芯片的关键阶段之一是当您获得第一个硅后面的测试。这是您终于看到所有仔细工作的结果,并确定芯片是否正在设计,并且随着模拟告诉您。这被称为IC验证。验证的重点是功能测试 - 检查硅中的芯片是否满足原始要求。这通常涉及一定量的表征以及基本功能的测试,以确保在设计中没有被剥落任何错误。

验证步骤与生产测试分开,其中重点是快速准确地找到具有制造缺陷的任何芯片,以便它们可以被丢弃。在这里,重点通常在最快的时间内完成测试到可接受的准确性水平。这是因为每芯片的成本将随着每次额外的第二次筹码在测试仪中花费而增加。

In contrast, in the validation step the primary focus is generally not on the speed of the testing but on the quality of the data you can extract from the chip. This is not to say that speed is irrelevant, and if you can get good results quickly, then that is always a good thing. Building automation into the testing process at the validation stage has numerous benefits:

  • 加快测试

通过自动化测试,可以以更有效的方式执行它们。有可能在先前的测试完成后,每个测试都排列并准备开始。还可以在24/7运行的测试,而无需工程师向夜班工作。

  • 流程改进

任何类型的自动化的最佳方面之一和通常被忽视的方面是它形成过程改进的基础的方式。在其心脏中,自动化测试是该测试所需步骤的具体表达。描述它们使得能够分析每个步骤;然后可以从该分析中学习任何学习,然后送回算法,然后对所有用户提高。通常情况下,工程师可能会在更好的做事方式中手动绊倒,但这些学习通常不会回到过程中。

  • 更一致的测试

根据定义,自动化测试是可重复的,因此自动化允许在给定批次中更加一致地测试芯片。这允许更好地比较每批或批次之间的样本之间的表征数据。

  • 直接应用用于模拟开发的测试

由于芯片在磁带外验证阶段已经广泛模拟,因此您已经拥有大型的测试库和预期输出。在验证阶段,您可以实际上可以以非常容易地验证的方式设计这些验证测试。这极大地加快了整个验证练习,并允许在不同阶段进行测试的一致性。

  • 远程工作验证

It is often beneficial for designers at all levels to see the outcome of their work. However, validation testing may often happen in a different geographical location. Having an automated system that can be accessed remotely can let designers get hands-on experience with the silicon they helped to produce. This can help them to improve their skills over time, as well as help them gain valuable insight into how the chip was designed, and this information be constantly available to the validation team. There are also obvious advantages to remote work given the current situation with Covid-19 and lock downs across the world.

  • 验证流程

考虑到所有这些因素,Adesto已经开发了Python based testing framework that integrates all of our instruments together in the lab and allows us to quickly port tests that were developed in the verification stage to validation tests. The Python language was chosen to automate the tests due to its familiarity amongst the testing engineers as well as the numerous libraries that were available to help with the work.

The validation system itself consists of a board with socket for the chip under test. The board contains a daughter card with a large Xilinx FPGA connected via ethernet to the lab’s network. We can program the FPGA remotely over the network and use it to control all the digital inputs of the device under test (DUT) and also monitor its outputs. Various analog inputs and outputs from the DUT are hooked up to switches that can switch them to a set of SubMiniature version A (SMA) connectors which are connected to scopes, spectrum analyzers and signal sources. We can also remotely control each of these instruments, and together it means that all the inputs, outputs, analog and digital signals from the DUT can be forced to whatever values we want to observe.

Python测试框架软件在远程服务器上运行。我们的验证工程师可以在Python中编写测试,并将其与C编程代码相结合,可以在DUT中的嵌入式处理器上运行。这提供了通过其全套功能测试锻炼ASIC的能力。与仪器和测试板的所有连接都是通过网络的,因此可以远程进行测试的开发和执行。

我们的远程IC验证测试工具由我们的全球自定义ASIC设计团队定期使用,以增强协作和监督。当我们期待着不同的未来工作的不同,我们许多人都在家工作了一段时间,这样的解决方案可以确保我们的客户的ASIC设计按时安全地交付,并具有他们期望的高质量。看看这个简短视频to find out more about custom ASICs.