The AE32000 processor core, developed by Advanced Digital Chips Inc., Korea, is used primarily in the embedded processing environment. The AE32000 simulator models this embedded processor core having high code density. An enhanced simulator was developed to study the performance of the present Instruction Set Architecture after comparison with the Simplescalar ARM simulator. ARM is among the most widely used processor cores for embedded applications and so was chosen for this comparison. Code density of the AE32000 is very high because of its shorter instruction length. This results in a smaller footprint inside the memory. But the longer instruction length of the ARM proves better when it comes to performance. The LERI(Load Extension Register Immediate) unit of the AE32000 has a special role before instructions that need long immediate values during execution. / Graduation date: 2004

Power optimization becomes more and more important due to the design cost and reliability. Sometimes high power consumption means expensive package cost and low reliability. The first step in optimizing power consumption is determining where power is consumed within a processor. While system-level code tracing and bit transition calculation are not enough to estimate the power distribution, transistor-level HSPICE simulation to model a microprocessor is too complex and time-consuming. In our research, a VHDL model with enhanced signal tracing function will be developed based on the existing VHDL behavior model. The power consumption of superscalar microprocessor in terms of switching activity and capacitance will be carefully studied. Two factors served as the basis for study: accessibility and importance for power calculations. A brief examination of the datapath suggests that the register file, the instruction cache and data cache are some of the major contributors to power usage. It was therefore decided to track the input and output bit transitions to these modules. These transitions are counted along with the number of accesses to each of the modules. In order to gather all of this data, the original VHDL model simulator has been enhanced. As instructions pass through the CPU, additional code is required to track and record the necessary information. For each individual instruction in the ISA, various information is recorded based on the elements in the processor that the instruction affects. For instance, if the simulator is about to execute a load instruction, the instruction uses the programmer counter, the instruction bus, data bus, the address bus, the ALU (adder) and the register file. The information being recorded for each of these elements must be updated to reflect the execution of that particular load instruction. Also, the inside circuit of each module, i.e. register file, instruction cache and data cache and the 6-transistor memory cell layout considering the 0.25��m CMOS technology will be studied in order to extract the capacitance. We do not need very accurate, absolute power estimation, therefore, we will try to keep the model simple. / Graduation date: 2000