• The Journal of Korean Institute of Communications and Information Sciences
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• v.27 no.4C
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• pp.388-397
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• 2002

We designed a SIMD-DSP/FPU that can efficiently improve multimedia processing performance when integrated into high-performance embedded microprocessors. We proposed partitioned architectures and new schemes for several functional units to reduce chip area. Sharing functional units reduces the area of FPU significantly. The proposed architecture is modeled in HDL and synthesized with a 0.35$\mu\textrm{m}$ standard cell library. The chip area is estimated to be about 100,000 equivalent gates. The designed unit can run at higher than 50MHz clock frequency of CPU core under the worst-case operating conditions.

• IEMEK Journal of Embedded Systems and Applications
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• v.5 no.1
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• pp.23-28
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• 2010

The automotive industry tries to provide infotainment systems to emerging automobiles. Since the infotainment systems require various peripheral devices and network connectivity, legacy operating systems such as Linux and Windows can be much preferred due to its plentiful device drivers and multimedia applications while the operating systems following OSEK standard are used for automotive electronic control units. Thus it is highly desired that the system software supporting infotainment applications can be portable over different legacy operating systems providing unified programming interfaces. The majority of legacy operating systems support POSIX interfaces for application development. MOST is an automotive network standard for infotainment systems. Network Service defines the protocol stacks for MOST control data, which is essential to implement infotainment applications over MOST. In this paper, we suggest a POSIX-based Network Service so that we can utilize legacy device drivers and applications for automotive infotainment systems. We measure the performance of the POSIX-based Network Service and show that its overhead is not significant.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2009.05a
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• pp.903-906
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• 2009

In this contribution, we designed a serial port interface (SPI) suitable for embedded systems, especially for Bluetooth baseband. Proposed architecture is compatible for the APB bus in AMBA bus architecture. The 8-bit design of the SPI module is in charge of transferring the data and the instructions between the external devices and the coprocessors. We adopted the cyclic redundancy check method for the error correction. Also, we provided the interface for multimedia cards. The designed SPI module was automatically synthesized, placed, and routed. Implementation was performed through the Altera FPGA and well operated at 25MHz clock frequency.

• IEMEK Journal of Embedded Systems and Applications
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• v.6 no.6
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• pp.393-400
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• 2011

Recently, demands of information devices are increasing as we can find so many information devices around us such as smartphone, MID(Mobile Internet Device), Tablet. These characteristics of information devices services should support soft real-time based time guaranteed multimedia services and control internet appliances. In this situation, soft real-time supported system should be developed to consider as a total aspect of hardware, kernel, middleware, application. But this paper will describe soft real-time supporting and evaluation methods for information device as an aspect of only kernel.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.41 no.4
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• pp.83-90
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• 2004

In this paper, we proposed a new instruction set(X32Y ISA) with 3 different types of instruction mode. The proposed instruction set organizes 32-bit, 24-bit, 16-bit instruction in order to solves a problem of memory size limitation in an embedded microprocessor. We designed a 32-bit 5 stage pipeline RISC microprocessor based on the X32V ISA. To verify the proposed the X32V ISA and a microprocessor, we estimated a program code size of multimedia application programs using a X32V simulator. In result, we verified that the Light mode and the Ultra Light mode obtains 8%, 27% reduction of a program code size through comparison with the Default mode. The proposed microprocessor was verified all X32V instructions execution at Xilinx FPGA with 33MHz operating frequency,

• The Journal of Korean Institute of Communications and Information Sciences
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• v.34 no.10C
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• pp.983-991
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• 2009

While H.264/AVC is in wide use for multimedia applications such as DMB and IPTV service, we have limited usage cases for embedded real-time applications due to its high computational demand. The paper provides judicious guide line for optimization method selection, by presenting the detailed experiments data through the development process of a real time H.264 software encoder on embedded DSP. The experimental analysis includes an intensive profiling analysis, fast algorithm application, optimal memory assignment, and intrinsic-based instruction selection. We have realized a real-time software that encodes CIF resolution videos 15 fps on TMS320DM64x processors.

• The KIPS Transactions:PartA
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• v.13A no.7 s.104
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• pp.589-598
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• 2006

In this paper, we describe the development and optimization of an embedded Biuetooth solution on an SoC platform for real-time audio streaming over a Bluetooth wireless link. The solution includes embedded Bluetooth protocol stack and profile simplemented on a virtual operating system for portability, and other optimization techniques to fully exploit the benefits of multimedia-oriented SoC. The optimization techniques implemented in this paper are memory access minimization by using on-chip scratch pad memory, codec library optimization with DSP and parallel memory access instruction set, and dynamic audio quality adjustment regarding current wireless link status. Experimental results show that the optimized solution presented in this paper can support high-qualify audio streaming without the support of external memory.

• Proceedings of the IEEK Conference
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• summer
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• pp.204-208
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• 2004

Embedded business will be expanded market more and more since customers seek more wearable and ubiquitous systems. Cellular telephones, PDAs, notebooks and portable multimedia devices could bring higher microprocessor revenues and more rewarding improvements in performance and functions. Increasing battery capacity is still creeping along the roadmap. Until a small practical fuel cell becomes available, microprocessor developers must come up with power-reduction methods. According to MPR 2003, the instruction and data caches of ARM920T processor consume $44\%$ of total processor power. The rest of it is split into the power consumptions of the integer core, memory management units, bus interface unit and other essential CPU circuitry. And the relationships among CPU, peripherals and caches may change in the future. The processor working on higher operating frequency will exact larger cache RAM and consume more energy. In this paper, we propose advanced low power trace cache which caches traces of the dynamic instruction stream, and reduces cache access times. And we evaluate the performance of the trace cache and estimate the power of the trace cache, which is compared with conventional cache.

• IEMEK Journal of Embedded Systems and Applications
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• v.6 no.3
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• pp.190-200
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• 2011

Android platform provides a content provider and a cursor mechanism to access the internal SQLite engine. Content providers not only store and retrieve data but also make it accessible to applications. Applications can only share data through content provider, since there's no common storage area that Android packages can access. Cursor is an interface that provides random read-write access to the result set returned by a database query. However, this cursor possesses two major limitations. First, a cursor does not support a join clause among cursors, since the cursor can only access a single table in the content provider. Second, the cursor is not capable of creating user-customized field in the predefined content providers. In this paper, we propose the unified cursor architecture that merges several cursors into a single virtual cursor. Cursor translation look-aside buffer (TLB), column windowing mechanism and virtual data management are the three major techniques we have adopted to implement our structure. And we also propose a delayed synchronization method between an application and a proposed unified cursor. An application can create a user-customized field and sort multiple tables using a unified cursor on Android platform.

• The KIPS Transactions:PartA
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• v.14A no.5
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• pp.295-300
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• 2007

The Linux-based embedded systems such as mobile telephones. PDAs and MP3 players are widely in use. USB(Universal Serial Bus) is the interface for data communication between the computers and these peripheral devices. Some embedded systems like intelligent home networking and multimedia streaming require guaranteed QoS(Quality of Service), which is needed for real time transmission of UDP/IP messages through USB. Although USB Ethernet driver is supported by USB Gadget API in Linux, it is unable to provide the desirable QoS required by each type or small embedded systems due to the unpredictability or TCP/IP Stack in Linux. This paper proposes IP-Over-USB to improve QoS of UDP/IP message transmission in the embedded systems using USB in Linux system.