Software-Based Side

The software-based side of PODER rehes on adding extra instractions into the original program code, so that it can send data to the hardware-module and, by doing so, control it. From the four types of control flow errors mentioned before that PODER aims at, the software-base side is responsible for protecting the system against incorrect jumps to the same BB (1) and incorrect jumps to the begitming of a BB (2). 

The decoder module reads the data and address buses between the processor and the memory looking to store irrstmctions in the program memory area. Whenever a store instruction is found, it reads the address bus to check which address the processor is accessing, in order to decode the instraction from the software-based side, and reads the data bus to read the value being sent. It then manages to perform the... 

OCFCM is expected to detect control flow faults that either causing the PC to freeze at the same memory address (through the watchdog) and the ones that break the sequential evolution of the PC with an inconsistent destination address. Unfortunately, these two cases do not comprehend all types of control flow errors. An incorrect decision, whether to take or not the branch, cannot be detected by the module. Therefore, a software-based side is required, with the Inverted Branches technique. 

The software-based side on OCFCM is responsible for choosing which module will be active (when using a set of OCFCM) and performing the transformation on the software that implements the Inverted Branches software-based technique. It also has to guarantee that the program code does not use jumps with dynamic destina-... 

In the next subsections, the terminology used for HETA is presented, as well as the hardware-based and software-based sides of the technique. 

The software-based side from HETA is responsible for parsing the code and generating the assertions to be added to the program code. Also, it transforms the program code so that it keeps a global register updated with the current signamre in effect... 

The hardware module was implemented in VHDL language, based on a timer that signals an error if not reset. To calculate the XOR value, we added a 16-bit accumulator register that performs a XOR operation between its current and new values so that it is not only able to calculate the real-time XOR value, but also to stores it. A decoder was also added to identify instructions from the software-based side. 

The data from sensory evaluation and texture profile analysis of the jellies made with amidated pectin and sunflower pectin were subjected to Principal component analysis (PC) using the statistical software based on Jacobi method (Univac, 1973). The results of PC analysis are shown in figure 7. The plane of two principal components (F1,F2) explain 89,75 % of the variance contained in the original data. The attributes related with textural evaluation are highly correlated with the first principal component (Had.=0.95, Spr.=0.97, Che.=0.98, Gum.=0.95, Coe=0.98, HS=0.82 and SP=-0.93). As it could be expected, spreadability increases along the negative side of the axis unlike other textural parameters. 

Following the state-of-the-art review, the next step is to implement fault tolerance techniques. We will start by explaining in detail and implementing two known software-based techniques, called Variables and Inverted Branches (AZAMBUJA 2010b), which will later be used as a complement to hybrid fault tolerance techniques. These techniques have been proposed in the past years and achieved high fault detection rates at low performance degradation levels and therefore are useful not only as an introduction to software-based fault tolerance techniques, but also to be combined with hardware-based and hybrid techniques. Then, three novel hybrid techniques will be proposed and implemented, based on both software and hardware replication characteristics. The three hybrid techniques will be divided into their software and hardware sides and described in detail, concerning both operation description and implementation. 

The technique is divided in software-based and hardware-based sides, which communicate through memory writes at predefined memory addresses. In order to do so, PODER exploits two main concepts ... 

OCFCM itself is defined as a non-intrasive hardware module and therefore corrld be considered a pure hardware-based technique. Irrstead, OCFCM alone cannot achieve its main objective, which is detecting control flow errors. To do so, it has to be complemented by the Inverted Branches software-based technique (described in Sect. 4.3) and configured by the apphcation running in the processor. Because of these characteristics, it is considered as a hybrid farrlt tolerant technique, even if not as tightly coupled with the software-side as PODER. 

Like PODER and OCFCM, HETA can also detect control flow loops (4). In order to detect this kind of error, a watchdog timer is implemented. The counter is reset every time the software-based technique side enters a BB, by performing a Reset XOR instruction. When the counter overflows, an error is flagged. By doing so, the hardware module can detect a control flow loop that causes the execution flow to be stuck at a single instruction. 

Figure 6.10 shows the data flow of the software tool BayAPS PP for optimal capacity assignment for given stochastic demands. Transaction data about demand and inventories is typically imported from SAP R/3 as indicated, production capacity master data and side conditions are stored in the software tool. Forecasts can be taken from a forecast tool or from SAP R/3. The output ofthe tool is a list ofpriorities of products and their lot sizes, which are optimal based on the presently available information. Only the next production orders are realized before the computation is repeated, and the subsequently scheduled production is only a prediction. 

Testing should include network transactions under normal and high loads. For this test, refer to verifications in the TCP/IP transfer protocol. The advantage here is that this is built into the system and will be performed on an ongoing basis. However, this is not 100% accurate, as there are rare situations where the test does not work. To be on the safe side, use routines (e.g., MD5 hash calculation routines based on 128-bit strings). Ask the vendor of your application software sometimes, such tests are built in. 

Early on, it was anticipated that many repetitive calibrations and EMF measurements would be carried out in the evaluation of a large quantity of electrodes. The first microcomputer-based automated titration system utilizing high level software (CONVERS) hastened these studies (10), as did a more recently constructed minicomputer system (Figure 1). Typical results are shown in Figure 2, where a set of five protriptyline CWEs were calibrated simultaneously (11). Graphic side-by-side comparison of different electrode calibrations was also useful in establishing structure-selectivity relationships. 

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