Subject was to find out if a Thermal Inkjet Cartrige is dryed out, empty, damaged or ok. The task should be gained with electrical measurement and the appropriate interpretation of these results. If a solution is found, the developed circuit could be integrated on the printhead silicon chip to send a state message to the printer (see Part A). Because the expected results did not occure, the original task had to be adapted and a cartrige tester was realised in the remaining time instead. (see Part B).

Part A (U and I real-time Measurement):

To get into the subject, the understanding of the printer technology was the first approach. A nozzel that shoots a tiny drop of ink to the paper consists basiceally of a heating chamber. A thin film resistor gets hot when current is passed through it. The ink above the resistor is expanded and is shot out of the firing chamber as a result. Measurement of printer control electronic signals was of need to generate the firing signals independent of the printer. Measurement results of the current-characteristic did not correspond with our expectations and no difference between characteristics of a full and empty cartrige could be found. With our knowledge and resources a statement of the cartrige state cannot be made. Further research, mainly from the physical point of view, is necessary to achieve the gain.

Part B (Cartrige Tester):

After the milestone decision to give the project a new direction, a cartrige tester was successfully developed. It is capable to differentiate between a damaged and a principally working ink cartrige. However it cannot distinguish between an empty and a dryed out ink cartrige The hardware of the cartrige tester was designed to measure the value of each resistor integrated on the printhead chip for future developments.

Task:

With the project work 'fibre-optical video transfer' (PA 1.15, summer term '99, Kuster, Thomi, Töngi) we formed the basis for a universally applicable video conference system. The aim of this diploma work was to come a large step closer to the final product - a conference system. Concretely: We set ourselves the goal to have a demo application of a video conference system at the end, with which we are able to transfer a digitized and compressed video signal in PAL standard through a fibre bus system.

Status of the work:

At the end of this diploma work we can offer a unidirectional system (transmitter-receiver-system). On the transmitter side, a PAL video signal is digitized, compressed and serially sent through the plastic fibre line. On the receiver side, the data are decompressed and emitted as an analogue PAL video signal. The bit rate of the video data stream amounts to 8MBit/sec. Our system is openly structured so that an integration of audio and control data is simply realizable in the next step of development. Appropriate substitutes of these signals are already transmitted. In order to demonstrate the simplicity of the integration of control data, we have implemented a small additional application. So we are able to transmit text characters from terminal to terminal (unidirectional) via the plastic fibre.

The task of this thesis was to develop a system, which fades a video signal into a LCD display. A such solution could be inserted for video conferences or control installations.

The realised system sits together from a hardware - and a software part. The hard-ware is composed of a PCB (Print Circuit Board), which is firmly installed as an inter-face between the PC and the display. Central blocks on the print are a video input processor, which transforms the analogous video signal in a digital 16Bit RGB sig-nal, a fast, 1 MB large SRAM - bank as well as a FPGA, which contains different soft-ware modules and controls the entire system. This software was written in the hard-ware description language VHDL.

The display data, which are coming from the PC, are transmitted either directly at the display or replaced through the digitised video data. The main problem was the synchronisation of the different cycle rates of the video data and the PC display data.

To solve this problem, a virtual Dual Port RAM was developed. Thereby data A with the address A and the speed A can be written in the RAM. Simultaneously data B with the address B and the speed B are selected from the RAM. So the video picture is written continuously in the RAM, at the address to be faded in the display and is picked out of the RAM then again. The said Dual Port RAM functions as follows: Within a period of the 25 MHz display clock the RAM is described per once and chosen once. For an operation at the RAM only 20ns are available. Initial fears, that this short time could cause prob-lems, proved as immaterial.

The points listed in the task designation could be realised: A moved video picture can be projected in the LCD display. Also the options PCB with a FPGA, RAM's and an analogue-digital converter as well as adjustable picture sizes on -, - and full-length portrait were fulfilled. Additional the outlook no picture' is possible and the picture can be frozen.

Introduction

A growing number of integrated systems consist not only of digital components but also of ana-log parts. For the prototyping of digital systems, programmable logic is a fast and convenient way, whereas for development of analog circuits no equivalent method exists. To meet this need, the idea arose to manufacture a new printed circuit board capable of fast prototyping of mixed signal circuits, mainly for educational purposes (i.e. microelectronics engineering trai-ning courses).

Action

Because of mechanical and electrical considerations, it was reasonable to break down this board into two independent parts: a digital and an analog module. All analog subsystems can be individually interconnected with wires. Clock generation for the SCF is obtained either by applying an external clock signal or using the internal clock generator which provides a signal, phase locked to the output of the ADC.

The digital subsystem can either be configured with a PC application or, in stand alone mode, with a set of DIP switches. The analog module includes: 4 configurable analog blocks, a two-channel switched capacitor filter with biquad structure (2nd order) and a quad analog switch.

The digital module consists of: a programmable logic device (i.e. an Altera EPF10K200S), a universal asynchronous receiver transmitter for communication with a PC 2 analog-to-digital converters, one for control system applications, the other for digital audio purposes 2 digital-to-analog converters, corresponding to the ADCs a digital audio interface (S/P-DIF), both a receiver and a transmitter a programmable clock generator 128 kByte of static random access memory some user programmable light emitting diodes and switches

Results

The printed circuit board of the analog module has been designed, layouted and manufactured completely. The work for the board of the digital part, however is still in progress.

Microelectronic was given birth by Texas Instruments in the year 1958. The IC-Technology has been developed very quickly. At present it is one of the most increasing and changing field in engineering science. That creation forty years ago was one of the most important milestones in the history of electronic engineering, beneath the invention of the transistor. It is understood that this little piece of silicone has changed the world and has become a large branch of industry with a turnover of several 100 billion Dollars yearly. One forth of the amount is made out of Application Specific Integrated Circuits, called ASIC. The topic ASIC is divided into three parts: programmable ASIC, Semi Custom ASIC, Full Custom ASIC. In the Meanwhile the ASIC business has become as large that there is almost no chance to keep the overview. That is especially a big problem for small firms, which want to step forward to this technology. This fact was the reason to launch this project. My goal was to consult small firms, which might include an ASIC in their product. It was planned to downsize this problem by a service. After the first meetings with three companies, we recognize that these firms had no need for our service. Constrained by the reality we had to set new objectives. The output of the reorientation is this thesis. My new goal is to give an overview of the complex and large ASIC business. It deals with the following topics: showing the disadvantages and advantages of the different ASICs and their usage, giving an overview about the present technology and the trends in ASICs, pointing out the different design flows and the costs, decision of the right ASIC, project and product management, specification of an ASIC project.