Constraint Models of SDRAM-Based Arbitrary Waveform Generator
Yindong Xiao, Gongbai Xiao, Ke Liu, Zaiming Fu, Houjun Wang · IEEE Transactions on Instrumentation and Measurement · 2023
In the design of SDRAM-based arbitrary waveform generators, the conflict between the randomness of dynamic memory output data flow and the requirement of seamless signal output is a non-negligible problem, especially in generators with hopping functions and high sampling rates. By imposing appropriate constraints in the design, the continuity of the output signal and the high throughput utilization can be guaranteed, and the constraints can be modeled to obtain the design boundary requirements under different specifications. In this paper, we analyze the throughput model of SDRAM and the access characteristics of an arbitrary waveform generator with jump capability. We establish a minimum waveform segment length model and a buffer size model to guarantee continuous signal output, which can obtain sufficient conditions for seamless synthesis of arbitrary waveform generators and be used to support the repeat/jump function of multi-segment waveforms. Experimental results on a DDR3 SDRAM-based generator show that the minimum waveform segment length obtained is within 11 words of the measured boundary, and the minimum buffer size is within 10 words of the measured boundary, which can effectively improve hardware resource utilization.