基于CoreConnect的OPB SPI接口设计与实现

针对SPI接口传输速率低、CPU利用率低、主从机配置固定和从机选择单一等问题,提出一种基于CoreConnect总线的OPB SPI接口设计方案。添加缓冲FIFO、SCK时钟波特率寄存器、连续发送间隔寄存器,采用可扩展从机模式,设计出传输高效、主从灵活可配、多从机选择可配的OPB SPI 接口。仿真测试表明该接口的有效性和可行性,能够满足SOC系统的需要。     

Applying grounded theory to understand software process improvement implementation: a study of Brazilian software organizations

Despite the fact that organizations recognize the importance of implementing software process improvement (SPI) to enhance software development capabilities, recent studies show that many organizations still struggle to successfully implement SPI. These studies demonstrate that most SPI initiatives fail due to their incapacity to overcome social–cultural critical barriers, such as lack of motivation and higher management support. Therefore, the accurate understanding of the context where SPI occurs may facilitate the development of more efficient SPI implementation strategies aiming to overcome those difficulties. The objective of this work was to present a Grounded Theory-based study that investigated SPI implementation initiatives conducted by Brazilian software organizations. The main product of this study is a theoretical framework that tries and explains the phenomenon associated to the success of SPI implementation initiatives. The theoretical framework constituted a set of interrelated SPI domain entities supported by a set of propositions assessed by experienced Brazilian SPI consultants. We expect that such theoretical framework can facilitate SPI implementation by providing better understating of the dependency relationships among critical success factors that may jeopardize SPI initiatives.     

Modelling the Likelihood of Software Process Improvement: An Exploratory Study

Software process assessments have become big business worldwide. They can be a powerful tool for initiating and sustaining software process improvement (SPI). However, SPI programs sometimes fail. Moreover there still are very few systematic empirical investigations about the conditions under which SPI initiatives vary in their outcomes. In this paper we present the results of a study of factors that influence the success of SPI. The data come from a sample survey of organizations that have performed assessments based on the capability maturity model for software, and was conducted from 1 to 3 years after the assessments (sufficient time had passed for changes to have taken place). The results consist of a multivariate model of the conditions (e.g., how the improvement efforts are organized and funded) that can explain the successes and failures of SPI efforts. The model is constructed using a classification tree algorithm. It identifies the most important factors that affect the outcome of SPI efforts, and describes how those factors interact with each other to influence success or failure.     

SPI总线接口扩展与应用

在众多型号的单片机中,有许多不带SPI串行总线接口,从而限制了其对SPI总线接口器件的使用.本文介绍了SPI串行总线的特征和时序,对无SPI总线接口的单片机采用其I/O端口,通过程序控制的方法,模拟SPI串行总线接口,使其能与SPI总线接口的器件之间进行数据传送,并以串行E2PROM应用为例,介绍了模拟SPI串行总线接口的使用方法.     

Software Process Improvement barriers: A cross-cultural comparison

ContextSoftware Process Improvement initiatives have been around for many years with the growing globalisation of software development is making them increasingly important.ObjectiveThe objective of this exploratory research is to gain an in-depth understanding of barriers that can undermine SPI, in the context of Global Software Development, from the perspective of software development practitioners; this will enable SPI managers to better manage SPI initiatives. We intend to discover if the barriers to SPI initiatives in a developed country are different to those in a developing country.MethodIn an empirical study, Vietnamese software practitioners’ experiences of SPI barriers are compared with barriers identified by Australian practitioners. Face-to-face questionnaire-based survey sessions with 23 Vietnamese SPI practitioners were conducted. Our survey included barriers to SPI improvement initiatives identified in previous research. We asked the participants to rank each SPI barrier on a three-point scale (high, medium, low) to determine the importance of each barrier. We then compare our results, with results (identified in previous work), from 34 Australian software development practitioners.ResultsWe identify (1) lack of project management, (2) lack of resources, (3) lack of sponsorship, (4) inexperienced staff/lack of knowledge, and (5) lack of SPI awareness as ‘high’ value SPI barriers in Vietnam. The results also reveal similarities and differences between the experiences of Australian and Vietnamese practitioners regarding the importance of the SPI barriers identified. While the Australian practitioners were also concerned with (1) lack of SPI awareness, they were even more concerned with (2) organisational politics, and (3) lack of support.ConclusionsPractitioners identify SPI barriers based on previous SPI implementation experience. Their role(s) in their different organisations have helped them to understand the importance of that barrier. Vietnamese software practitioners cited more SPI barriers than their counterparts in Australia. The Vietnamese SPI barriers relate to project management, resources, and sponsorship while the Australian barriers are concerned with organisational politics and lack of support.     

Software process improvement with weak management support: an analysis of the dynamics of intra-organizational alliances in IS change initiatives

Software Process Improvement (SPI) projects are large-scale, complex organization-wide change initiatives. They require considerable investments in personnel, time and money and impact just about every aspect of software firms. The group charged with conducting an SPI project has, however, little formal authority to influence or force software professionals to engage in SPI work or to define and implement changes. The SPI literature suggests that successful SPI initiatives depend on strong commitment from top management. But what should the SPI group do if management support is weak? In this paper, we present an analysis of how an SPI group can use alliances to obtain influence and succeed when management support is weak. Our study is based on a 3-year longitudinal field study of SPI change initiatives at Denmark Electronics. Our findings show that a lack of top management support is not necessarily incompatible with success. This research opens an important new area of research on intra-organizational alliances and information system (IS) implementation. It has the potential to offer new theories and practical advice on how IS implementation projects can be more effectively managed.     

基于SPI协议的MMC卡读写机制的实现

多媒体卡 (MMC)是在多媒体领域被应用很广的外部存储介质 ,可是大多数微处理器 (MCU)并没有专门的多媒体卡控制器。串行外设接口 (SPI)协议是被广泛支持的总线协议 ,仅需四根线就可以完全解决读写的问题。多媒体卡的串行外设模式给了不具有多媒体卡控制器而需要读写多媒体卡的微处理器另一种选择 ,它通过串行外设接口总线与多媒体卡相连 ,并支持多媒体卡模式下的大多是指令。该文介绍了串行外设接口协议的原理和多媒体卡的串行外设接口协议模式的特殊性 ,最后通过DPS5 685 8平台实现。虽然在速度上比用多媒体卡控制器实现略慢 ,可是已经完全能够满足大多数的应用场合。     

一种基于Winsock2 SPI架构的网络监控程序自我保护方案设计与实现

如何保证涉密网络信息保密的问题一直受到政府、军队、航天等涉及国家秘密的行业所关注。在软件层次对计算机用户进行监控是一个较好的解决方案。这篇文章提出并实现了基于Winsock2 SPI框架的网络监控自我保护方案。监控程序本身的自我保护技术是保证网络监控抵抗非法用户攻击的关键。基于这种方案的网络监控程序能够将监控线程同系统关键进程进行绑定,既实现了程序的进程隐藏,又能够防止高级非法用户强制关闭监控程序,并且能够同Rootkit技术等其他相结合共同提高程序自我保护性能。     

智能家电终端无线通信接口的设计

针对现有的智能家电终端中多种无线通信技术之间互联的缺陷,设计了一个新的两种无线通信模块,由高性能的射频发射芯片nRF905和Philips公司的单片机P87LPC764组成的智能终端使用的嵌入式无线通信接口,该接口既支持串行口或以并行接口形式为家电控制平台扩展通信接口;又可以通过nRF905以无线通信方式与智能家电网关连接,实现了家庭网络控制器和智能信息家电的无线数据传输,为扩充家电设备控制器的通信接口提供一条新的途径。     

基于FPGA和EMIFA的SPI控制器系统设计

为了在现有C6000系列DSP芯片上扩展多路SPI外围设备,提出了一种基于FPGA和EMIF接口的多路SPI控制器系统方案。该方案采用C6000系列DSP上的EMIF接口与FPGA进行数据交互,扩展出多路SPI控制器。在FPGA上实现了接口模块、寄存器读写模块以及多路通用SPI模块。在ModelSim环境下对所设计的SPI控制器进行了仿真实验,仿真结果表明SPI控制器可以进行全双工通信。随之,在DSP-FPGA集成计算机上进行了实物测试,扩展的SPI控制器外接具有SPI接口的CAN控制器芯片MCP2515,通过扩展的SPI控制器控制MCP2515的数据收发,测试结果显示DSP可以通过MCP2515与其它CAN设备进行通信,扩展的SPI控制器工作正常。     

MicroBlaze软核处理器的SPI控制器设计

设计了一种基于Xilinx公司提供的MicroBlaze微处理器的SPI控制器.该SPI具有可配置的分频器、三线—四线转换功能,同时可以根据外接的芯片SPI总线需求配置其数据发送的方式.该SPI控制器的逻辑功能在Modelsim下仿真结果正确,并且在Virtex-7芯片上运用此控制器配置多款高速数据转换器、时钟芯片等.验证结果表明,该SPI控制器具有使用灵活、便于移植、易于使用、可以同时配置多片器件等优点.     

Testing two different precipitation datasets to compute the standardized precipitation index over the Horn of Africa

Severe droughts are a frequent problem for the Horn of Africa. In this article, we test the possibility of using the standardized precipitation index (SPI) for monitoring drought conditions in this region. The SPI is a statistical indicator evaluating the lack or surplus of precipitation over different time scales, thus allowing the time-related impacts of the moisture deficit to be distinguished.

The SPI is calculated as a function of long-term average precipitation, using continuous, long-term series of historical accumulated monthly precipitation records. The SPI for a given rainfall amount is then given in units of standard deviation from the mean of an equivalent normally distributed probability distribution function. As a consequence, wetter and drier climates and periods can be represented and monitored in the same way.

For this study, the 3, 6, 9 and 12 month SPI values have been calculated for the period from 1985 to 2008 over the Horn of Africa using Global Precipitation Climatology Centre (GPCC) data and European Centre for Medium Range Weather Forecasting (ECMWF) ERA-40 reanalysis data interpolated to a 0.5° grid.

Both SPI datasets have been compared for selected time periods by means of a root-mean-square-error, correlation-coefficient and contingency-table approach. First results demonstrate the feasibility of using the SPI for drought monitoring at regional scales over Africa, but further investigation is needed in order to identify the most suitable precipitation dataset for the SPI computation over Africa.     

Underwater polarization‐based single pixel imaging

This paper extends single pixel imaging (SPI) to underwater scenario. Backscattering, which is a limiting factor for underwater imaging, is analyzed for the SPI, and the forward model of SPI under backscattering is formulated. Inspired by the polarization‐based descattering technique, we propose the two cross‐polarization SPI detection scheme to eliminate the backscattering light. The descattered image is reconstructed from the cross‐polarization data. Experimentally, we construct the underwater polarization‐based single‐pixel imaging system. And we test our scheme under different turbidity water. It is shown in experiments that our method can provide a clear image at turbid water of 32FTU, where the classical SPI has been severely contaminated by the backscattering, even under the best the polarization state.     

SPI演算规范的建模、实现验证研究

针对安全协议安全属性是否满足,缺乏有效性能评价方法的现状,大都使用SPI演算或相近的进程代数方法进行建模。利用这种方法不仅能够有效地形式化描述安全协议,并且能够对安全协议进行多方面的系统评价,但基本上没有说明怎么样寻找设计合适的验证工具,验证其安全属性实现的正确性。本文引入基于SPI演算的验证工具SPRITE来保证建模过程正确性,并设计给出实现映射的具体方法。本方法通过对典型的WOO-LAM单向认证协议予以说明,最后SPRITE产生的具体JAVA代码,给出了安全协议的安全属性,使形式化描述的协议的安全属性是否满足更接近于人的理解而不仅只是机器的解释。     

Business-oriented software process improvement based on CMMI using QFD

Software Process Improvement (SPI) has become the key to the survival of many software development organizations. As a follow-up of a previous paper on SPI for the CMM using Quality Function Deployment (QFD), a new SPI framework integrating QFD with the CMMI is developed. Similar to the earlier SPI framework for the CMM, the proposed SPI framework based on the CMMI using QFD aims to achieve three objectives: (1) to map process requirements, including business requirements, to the CMMI with the help of QFD; (2) to develop a method based on QFD for the integration and prioritization of requirements from multiple perspectives (groups); and (3) to be able to prioritize software process improvement actions based on process requirements.Process requirements from multiples groups of stakeholders (perspectives), including business goals, are integrated and prioritized. SPI actions are linked to these process requirements using QFD. Thus, the priorities of actions reflect the priorities of process requirements. By executing the actions with the highest priorities, the highest satisfaction level of process requirements can be achieved. One unique feature of the framework for the CMMI Continuous representation is that the priority values of these actions can be compared across PAs, even when the PAs attempt to reach different capability levels.     

Windows CE下基于SPI总线的双机通信技术

智能分析仪器要求在Windows CE系统下能够通过SPI总线实现副板与主板、主板与主板之间的数据传输。首先介绍了SPI双机通信的机理,其次分析了Windows CE下的中断处理机制的流程,最后从内核态的中断服务程序、驱动层的中断服务线程、流接口函数、驱动加载等方面实现了Windows CE下SPI双机通信的驱动程序。实验表明,两个智能分析仪器的主板之间能够可靠、稳定地传输数据。