Perlee C J, Casasent D P
Appl Opt. 1989 Feb 1;28(3):611-26. doi: 10.1364/AO.28.000611.
Optical systems and algorithms are presented for implementing digit-serial (or on-line) computations. These systems achieve high accuracy without the need for A-Ds and incorporate parallelism and carry-free addition to achieve high processing speed. On-line arithmetic allows parallel calculations to be performed by concurrent execution of operations. (Consecutive operations can start before all digits of the previous operations are available.) The algorithms are problem- and step-invariant and inherently allow variable precision as we show. To achieve parallelism, we introduce the modified signed-digit number representation into these algorithms and architectures. This results in new arithmetic rules (new addition rules, a different number of bits needed, a different number of cycles required) from those in conventional digital digit-serial systems. We include sufficient detail (not readily available elsewhere) needed for the design of the units we include. New architectures using optical bistable devices and optical interconnects are described that can implement digit-serial addition, subtraction, multiplication, and division algorithms in this new approach.
本文介绍了用于实现数字串行（或在线）计算的光学系统和算法。这些系统无需模数转换器即可实现高精度，并结合了并行性和无进位加法以实现高处理速度。在线算术允许通过并发执行操作来进行并行计算。（连续操作可以在前序操作的所有数字可用之前就开始。）如我们所示，这些算法具有问题和步骤不变性，并且本质上允许可变精度。为了实现并行性，我们将修改后的符号数字表示法引入到这些算法和架构中。这导致了与传统数字数字串行系统不同的新算术规则（新的加法规则、所需的不同位数、所需的不同周期数）。我们提供了设计所包含单元所需的足够详细信息（其他地方不易获得）。本文描述了使用光学双稳器件和光学互连的新架构，该架构可以用这种新方法实现数字串行加法、减法、乘法和除法算法。
