Abstract
As embedded system products change with each passing day, designers require a product development strategy that is flexible, fast, and low cost. In this thesis, a programmable embedded platform is proposed and our target is to design and implement an embedded platform based on a softcore processor. For wearable applications, two OpenCore-based embedded platforms are introduced. One is wearable monitoring system based on openMSP430 for biomedical signal pre-processing, and the other is wireless body area network transmitter based on modified oc8051. The monitoring system contains an analog front-end for measuring electrocardiography (ECG) and respiration signals, an embedded platform for signals pre-processing, a Bluetooth for transmitting data and a smart phone for receiving data and displaying pre-processed signals on screen. This embedded platform includes an openMSP430 softcore processor, some peripherals such as random-access memory (RAM), read-only memory (ROM), general purpose input/output (GPIO), universal asynchronous receiver/transmitter (UART) and serial peripheral interface (SPI). In addition, we use the set of development tools including compiler and assembler for software development. It also provides a methodology of designing openMSP430-based platform and synthesizes openMSP430 core with TSMC 0.18 um 1P6M process technology in this thesis. Under the 20 ns timing constraint, the total area of openMSP430 core including peripherals is 13 k gate counts. The designed platform is also verified and prototyped by Xilinx Spartan-3AN field-programmable gate array (FPGA) with 2,928 Look-Up-Tables (LUTs), 8 kB ROM and 512 B RAM. The monitoring system operates at 50 MHz clock rate and takes 3,732 system clock cycles on signal pre-processing by openMSP430 core. Various transmission baud rates which are 115.2 kbps, 57.6 kbps, 38.4 kbps and 19.2 kbps can be supported by the system. The average power consumption of whole system is 229 mW under 3.3 V operation voltage. The transmitter for wireless body area network (WBAN) consists of a 2-axis sensor, an analog front-end, an analog-to-digital converter (ADC), a digital-to-analog converter (DAC), a frequency synthesizer, a power amplifier and a digital core. The digital core is a modified oc8051 which is programmable for supporting multi-standard communication protocols in WBAN. For improving performance and reducing size, the designed transmitter is tapped out to a mixed-signal chip with TSMC 0.18 um 1P6M process technology. The total area of the chip is 7.09 mm2 and the digital core only accounts for 1.04 mm2. The power consumption of digital core is 908 uW under 1.2 V operation voltage and at 32 MHz clock rate.