Design and implementation of a low Power Java Coprocessor for dual-interface IC Bank Card

Java Card Coprocessor is used for implementing Java Card Virtual Machine by hardware. Java Card needs to run with low power consumption, especially in the field of contactless Java Card. In this paper, a previous designed Java Card Coprocessor^[2] is analyzed. This paper mainly focuses on the hardware implementation of the instruction set for Java Card Virtual Machine and its disadvantages. In order to reduce the power consumption, a novel instruction classification of Java Card Virtual Machine has been achieved. And because Java Card Virtual Machine is based on stack operation, a new operand stack is designed by changing the width of the operand stack to reduce the instruction execute times, the new Java Card Coprocessor is 40% faster than previous one at the same frequency. So we can reduce the frequency by 40% while operating the same instruction in the same time. The novel Java Coprocessor has been implemented by hardware and verified by FPGA. The power consumption of the novel Java Coprocessor is about 40% lower than the previous one.