An improved method of task context switching in OSEK operating system

Author(s):  
Zhaohui Wu ◽  
Hong Li ◽  
Zhigang Gao ◽  
Jie Sun ◽  
Jiang Li
Author(s):  
Zhaohui Wu ◽  
Hong Li ◽  
Guoqing Yang ◽  
Zhigang Gao ◽  
Pan Lv

Author(s):  
SHAKTIRAJ KUMAR CHAGANTY ◽  
B. LAVAN ◽  
DR.S.SIVA PRASAD

A real-time microkernel is the near-minimum amount of software that can provide the mechanisms needed to implement a real-time operating system. Real-time systems are those systems whose response is deterministic in time. In our research a 32-task Real Time Microkernel is designed using which multi tasking can be done on the targeted processor ARM7TDMI. Two sets of functions are developed in this research work. First one is Operating System functions and second is application functions. Operating System functions are mainly for carrying out task creation, multi-tasking, scheduling, context switching and Inter task communication. The process of scheduling and switching the CPU (Central Processing Unit) between several tasks is illustrated in this paper. The number of application functions can vary between 1 to 32. Each of these application functions is created as a task by the microkernel and scheduled by the pre-emptive priority scheduler. Multi tasking of these application tasks is demonstrated in this paper.


Author(s):  
E.A. Fischione ◽  
P.E. Fischione ◽  
J.J. Haugh ◽  
M.G. Burke

A common requirement for both Atom Probe Field-Ion Microscopy (APFIM) and Scanning Tunnelling Microscopy (STM) is a sharp pointed tip for use as either the specimen (APFIM) or the probe (STM). Traditionally, tips have been prepared by either chemical or electropolishing techniques. Recently, ion-milling has been successfully employed in the production of APFIM tips [1]. Conventional electropolishing techniques are applicable to a wide variety of metals, but generally require careful manual adjustments during the polishing process and may also be time-consuming. In order to reduce the time and effort involved in the preparation process, a compact, self-contained polishing unit has been developed. This system is based upon the conventional two-stage electropolishing technique in which the specimen/tip blank is first locally thinned or “necked”, and subsequently electropolished until separation occurs.[2,3] The result of this process is the production of two APFIM or STM tips. A mechanized polishing unit that provides these functions while automatically maintaining alignment has been designed and developed.


Author(s):  
J. C. Fanning ◽  
J. F. White ◽  
R. Polewski ◽  
E. G. Cleary

Elastic tissue is an important component of the walls of arteries and veins, of skin, of the lungs and in lesser amounts, of many other tissues. It is responsible for the rubber-like properties of the arteries and for the normal texture of young skin. It undergoes changes in a number of important diseases such as atherosclerosis and emphysema and on exposure of skin to sunlight.We have recently described methods for the localizationof elastic tissue components in normal animal and human tissues. In the study of developing and diseased tissues it is often not possible to obtain samples which have been optimally prepared for immuno-electron microscopy. Sometimes there is also a need to examine retrospectively samples collected some years previously. We have therefore developed modifications to our published methods to allow examination of human and animal tissue samples obtained at surgery or during post mortem which have subsequently been: 1. stored frozen at -35° or -70°C for biochemical examination; 2.


Author(s):  
E. Wisse ◽  
A. Geerts ◽  
R.B. De Zanger

The slowscan and TV signal of the Philips SEM 505 and the signal of a TV camera attached to a Leitz fluorescent microscope, were digitized by the data acquisition processor of a Masscomp 5520S computer, which is based on a 16.7 MHz 68020 CPU with 10 Mb RAM memory, a graphics processor with two frame buffers for images with 8 bit / 256 grey values, a high definition (HD) monitor (910 × 1150), two hard disks (70 and 663 Mb) and a 60 Mb tape drive. The system is equipped with Imaging Technology video digitizing boards: analog I/O, an ALU, and two memory mapped frame buffers for TV images of the IP 512 series. The Masscomp computer has an ethernet connection to other computers, such as a Vax PDP 11/785, and a Sun 368i with a 327 Mb hard disk and a SCSI interface to an Exabyte 2.3 Gb helical scan tape drive. The operating system for these computers is based on different versions of Unix, such as RTU 4.1 (including NFS) on the acquisition computer, bsd 4.3 for the Vax, and Sun OS 4.0.1 for the Sun (with NFS).


2007 ◽  
Author(s):  
Sean M. Polyn ◽  
Kenneth A. Norman ◽  
Michael J. Kahana

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