Saroja Kanchi, Nozar Tabrizi and Cody Hayden, Kettering University, USA

SMaRT is a 16-bit 2.5-address RISC-type single-cycle processor, which was recently designed and successfully mapped into a FPGA chip in our ECE department. In this paper, we use SMaRT to run the well-known encryption algorithm, Data Encryption Standard. For information security purposes, encryption is a must in today’s sophisticated and ever-increasing computer communications such as ATM machines and SIM cards. For comparison and evaluation purposes, we also map the same algorithm on the HC12, a same-size but CISC-type off-the-shelf microcontroller, Our results show that compared to HC12, SMaRT code is only 14% longer in terms of the static number of instructions but about 10 times faster in terms of the number of clock cycles, and 7% smaller in terms of code size. Our results also show that 2.5- address instructions, a SMaRT selling point, amount to 45% of the whole R-type instructions resulting in significant improvement in static number of instructions hence code size as well as performance. Additionally, we see that the SMaRT short-branch range is sufficiently wide in 90% of cases in the SMaRT code. Our results also reveal that the SMaRT novel concept of locality of reference in using the MSBs of the registers in non-subroutine branch instructions stays valid with a remarkable hit rate of 95%!

CISC and RISC comparison; Communication Security; Cryptography; Data Encryption Standard; Microprocessors; SMaRT