资料查阅
Per Unit（PU）
Per Unit格式，是TI的IQMath库中用到的一种数据格式，相关的数学函数包括_IQsinPU，_IQcosPU，_IQatan2PU等。
Per unit values are typically used for variables in control application and are used by the library. Per unit value is found by dividing the
current reading by the maximum value that can be read. For example, if the voltage sense max is 20 V and the instantaneous reading is 5 V, the per unit value is 5/20 = 0.25.
CLA相关的参考资料
CLA的一些特性：
==CLA不支持嵌套中断，而且可以不经过PIE模块直接接收中断，中断触发后的7个周期，第一条指令就进入到D2级。
==CLA的工作频率与CPU同频，且CLA的指令都是单周期
==CLA支持IEEE-754标准的单精度浮点计算和操作
==与定点相比，浮点更易于编程，可以省去代码中缩放和饱和处理相关部分，而且不存在溢出（上溢或下溢），执行周期数相较于定点更少
==CPU与CLA之间的数据转换可以在数据读取的过程中完成；例如CLA在读取内存中uint16_t的数据可以直接转换成单精度浮点数据。
==CLA是一个完全可编程的模块，内部没有集成加速某一算法的子模块
官方整理的链接：CLA: Frequently Asked Questions
** CLA VS C28x VS C28x+FPU **
To make sure we are on the same page, lets define the following instruction sets:
== C28x Instruction Set
This is the original fixed-point instruction set.
== C28x+FPU Instruction Set
This is the C28x Instruction Set plus additional instructions to support native single-precision (32-bit) floating-point operations. While the additional instructions are mostly to support single-precision floating-point math, there are some other useful instructions like RPTB (repeat block) included. Since they are part of the superset, and only available on devices with the FPU, we still refer to them as part of the FPU instructions.
== CLA Instruction Set
The CLA instruction set is a subset of the FPU instructions. A few FPU instructions are not supported on CLA - for example the repeat block is not supported. The CLA also has a few instructions that the FPU does not have. For example: the CLA has some native integer math instructions as well as a native branch/call/return.
