1-3hit |
Shingo TAKAHASHI Shuji TSUKIYAMA Masanori HASHIMOTO Isao SHIRAKAWA
In the design of an active matrix LCD (Liquid Crystal Display), the ratio of the pixel voltage to the video voltage (RPV) of a pixel is an important factor of the performance of the LCD, since the pixel voltage of each pixel determines its transmitted luminance. Thus, of practical importance is the issue of how to maintain the admissible allowance of RPV of each pixel within a prescribed narrow range. This constraint on RPV is analyzed in terms of circuit parameters associated with the sampling switch and sampling pulse of a column driver in the LCD. With the use of a minimal set of such circuit parameters, a design procedure is described dedicatedly for the sampling switch, which intends to seek an optimal sampling switch as well as an optimal sampling pulse waveform. A number of experimental results show that an optimal sampling switch attained by the proposed procedure yields a source driver with almost 18% less power consumption than the one by manual design. Moreover, the percentage of the RPVs within 1001% among 270 cases of fluctuations is 88.1% for the optimal sampling switch, but 46.7% for the manual design.
Konstantinos SIOZIOS George KOUTROUMPEZIS Konstantinos TATAS Nikolaos VASSILIADIS Vasilios KALENTERIDIS Haroula POURNARA Ilias PAPPAS Dimitrios SOUDRIS Antonios THANAILAKIS Spiridon NIKOLAIDIS Stilianos SISKOS
A complete system for the implementation of digital logic in a Field-Programmable Gate Array (FPGA) platform is introduced. The novel power-efficient FPGA architecture was designed and simulated in STM 0.18 µm CMOS technology. The detailed design and circuit characteristics of the Configurable Logic Block, the interconnection network, the switch box and the connection box were determined and evaluated in terms of energy, delay and area. A number of circuit-level low-power techniques were employed because power consumption was the primary concern. Additionally, a complete tool framework for the implementation of digital logic circuits in FPGA platforms is introduced. Having as input VHDL description of an application, the framework derives the reconfiguration bitstream of FPGA. The framework consists of: i) non-modified academic tools, ii) modified academic tools and iii) new tools. Furthermore, the framework can support a variety of FPGA architectures. Qualitative and quantitative comparisons with existing academic and commercial architectures and tools are provided, yielding promising results.
Rafael K. MORIZAWA Takashi NANYA
A known problem of the four-phase handshaking protocol is that a return-to-zero phase of the signals involved in the handshake is necessary before starting another cycle, in which no useful work is usually done. In this paper we first define an easy-to-write specification style to specify four-phase handshaking asynchronous controllers that can be translated to an STG to obtain a gate-level implementation using existing synthesis methods. Then, we propose an algorithm that takes the specification written using our specification style and finds an optimized timing in which the idle-phase overhead of its gate-level implementation is reduced.